Bundles · Squares · Underlayment · Cost
Roof Shingle Calculator
Enter your roof footprint and pitch — get the exact number of shingle bundles, squares, underlayment rolls, ridge caps, nails and a full installed cost estimate with labor. Built for homeowners and roofing contractors.
Roof Dimensions
Measure the footprint of each roof plane at the eaves — horizontally, not along the slope. The pitch multiplier below converts it to the true sloped area.
✓ preview: 40' 0" (480 in)
✓ preview: 30' 0" (360 in)
26.6° · 1.1180× area
Shingle Type
Waste Factor
Cuts at valleys, hips, rakes & damaged pieces
10%Cost & Labor
Zip code pre-fills typical installed labor for your region — edit either field to match your quote.
Your Roofing Estimate
Updates live as you type
Shingle Bundles
46
Roof geometry
- Footprint area
- 1,200 ft²
- Pitch multiplier
- 1.1180×
- Roof area
- 1,341.64 ft²
- Roof squares
- 13.42 sq
Full material list
- Order area (incl. 10% waste)
- 1,475.80 ft²
- Squares to order
- 14.76 sq
- Individual shingles
- 1,196 pcs(46 bundles @ 26 pcs/bundle)
- Underlayment rolls
- 2 × (1,000 ft²/roll, 1 layer)
- Hip & ridge length
- 40 ft · 2 cap bundles
- Roofing nails
- ≈ 4,784 (4/shingle)
- Shingle weight
- ≈ 1.61 tons (dumpster planning)
Budget estimate
- Material cost
- $1,748.00
- Labor (23.6 hrs)
- $5,312.90
- Estimated total
- $7,060.90
Typical range $6,354.81 – $7,766.99 · $526.29/square
How the Shingle Calculator Works
Four steps from tape measure to order sheet — the same math roofing suppliers use.
1. Measure the footprint
Measure each roof plane's length and width at the eaves, horizontally. Complex roof? Add a section per rectangle and the areas sum automatically.
2. Apply the pitch multiplier
The sloped surface is always larger than the footprint. A 6/12 pitch multiplies area by 1.118; a 12/12 pitch by 1.414. Enter x:12, degrees or percent grade.
3. Add the waste factor
Valleys, hips and rakes force cut-offs. Simple gables need ~10%, complex roofs 15–20%. The slider updates bundles and squares in real time.
4. Get the full order list
Bundles rounded up, individual shingles, underlayment rolls, ridge-cap bundles, nail count, total weight — plus material and labor cost by zip code.
When to Use a Shingle Calculator
A five-minute estimate here replaces a padded guess on the order sheet.
Planning a roof replacement and sizing the material order
Comparing contractor bids against your own numbers
Ordering shingles, underlayment and accessories for a DIY job
Budgeting a re-roof before talking to lenders or insurers
Learning the squares → bundles math the trade actually uses
How to Calculate Roof Shingles by Hand
Want to sanity-check the calculator? These five formulas produce the identical result.
The five core formulas
Footprint area
footprint = roof length × roof width
Per section; sum all sections for complex roofs.
Roof area (sloped)
roof area = footprint × pitch multiplier
multiplier = √(1 + (rise/12)²)
Squares
squares = roof area ÷ 100
1 square = 100 ft² of roof surface.
Bundles
bundles = (squares × 3) + waste, rounded up
3 bundles/square assumes 33.3 ft² per bundle.
Individual shingles
shingles = bundles × 29
29 strips is the standard 3-tab bundle count.
Pitch multiplier lookup table
The slope correction factor for every pitch from 1/12 to 24/12 — measure the footprint, then multiply.
1/12
4.8°
×1.003
2/12
9.5°
×1.014
3/12
14.0°
×1.031
4/12
18.4°
×1.054
5/12
22.6°
×1.083
6/12
26.6°
×1.118
7/12
30.3°
×1.158
8/12
33.7°
×1.202
9/12
36.9°
×1.250
10/12
39.8°
×1.302
11/12
42.5°
×1.357
12/12
45.0°
×1.414
13/12
47.3°
×1.474
14/12
49.4°
×1.537
15/12
51.3°
×1.601
16/12
53.1°
×1.667
17/12
54.8°
×1.734
18/12
56.3°
×1.803
19/12
57.7°
×1.873
20/12
59.0°
×1.944
21/12
60.3°
×2.016
22/12
61.4°
×2.088
23/12
62.4°
×2.162
24/12
63.4°
×2.236
Steep roofs move the number fast: a 12/12 roof has 41% more surface than the footprint it sits on, and a 24/12 roof more than doubles it. The multiplier is geometry — √(1 + (rise/12)²) — not a rule of thumb.
What is a square in construction?
A square is an imperial area unit used across the US roofing trade: exactly 100 square feet of roof surface. Suppliers price shingles, felt, labor and dumpster fees per square, which is why every result on this page converts your roof area to squares before counting bundles. A "3-bundle square" is the industry shorthand for a product that covers 33.3 ft² per bundle.
Worked Examples — Footprint to Bundle Count
Four real roofs, run step by step. Every number below matches what the calculator returns for the same inputs.
Example A · Simple gable
30 × 50 ft house at 6/12 pitch
Material cost ≈ $1,850–$4,600 for architectural shingles at $100–250/sq.
Example B · Small shed
12 × 16 ft shed at 4/12 pitch
One extra bundle covers the starter course and a few spare strips for repairs.
Example C · Measured hip roof
2,800 ft² measured area at 15% waste
Hip roofs multiply diagonal cuts — never use the simple-gable 10% waste here.
Example D · Steep two-story
2,000 ft² footprint at 8/12 pitch
Steep 8/12+ pitches slow the crew and add safety staging — labor, not just materials, climbs.
Choosing Your Shingle Type
The type you pick changes coverage per bundle, weight and cost — the calculator adjusts all of them when you switch. Wind ratings and warranties matter as much as price once the quote comes in.
| Type | Coverage / bundle | Strips | Weight | Wind rating | Lifespan & warranty | Material cost |
|---|---|---|---|---|---|---|
3-Tab Asphalt 3 bundles / square | 33.3 ft²/bundle | ~29 strips (12" × 36") | ~65 lb/bundle | 60–80 mph | 15–25 years20–25 yr warranty | $80–200 / sq$25–65 / bundle |
Architectural (Dimensional) 3 bundles / square | 32.3–33.3 ft²/bundle | ~21–26 strips (~14" × 39") | ~70 lb/bundle | 110–130 mph | 25–35 years30–50 yr warranty | $100–250 / sq$35–85 / bundle |
Premium Designer 4–5 bundles / square | 20–25 ft²/bundle | ~24 strips | ~75–95 lb/bundle | 110–130 mph | 30–50+ yearsLifetime (50+) warranty | $250–600 / sq$65–150 / bundle |
3-Tab Asphalt
- Cheapest option, light weight, classic flat look.
- A solid choice for rental properties and budget re-roofs in mild climates.
⚠ Thinner mat resists wind up to ~60–70 mph only, shorter lifespan, fades faster in harsh sun.
Architectural (Dimensional)
- Layered, shadow-rich profile that mimics wood shake.
- 110–130 mph wind ratings and the default choice on most US homes today.
⚠ Slightly heavier and pricier than 3-tab; overkill for sheds and short-term holds.
Premium Designer
- Slate- and shake-look laminates with the strongest warranties and curb appeal for high-value homes.
⚠ Heavy — some older roof decks need framing checks; highest material and labor cost.
Beyond Asphalt: Wood, Metal, Slate & Tile
Asphalt owns ~80% of the US residential market, but three other families are worth knowing — mainly because they change weight, lifespan and how the order is even sold.
Wood Shake (Cedar)
Natural texture and insulation, renewable material, individual shakes are easy to spot-replace, weathers to a silver patina many homeowners like.
⚠ Fire codes restrict wood roofing in some wildland-urban areas; vulnerable to rot, mold and termites; needs regular treatment and cleaning.
Metal Shingles & Panels
Extremely durable and fire-resistant, light enough for most existing decks, reflects summer heat and can trim cooling costs, fully recyclable.
⚠ Higher upfront cost; audible in heavy rain and hail; thin panels can dent or oil-can; expansion requires special fasteners and clips.
Slate
A natural stone roof that can outlast the house; non-combustible, colorfast and unmatched curb appeal on historic and high-end homes.
⚠ Very heavy — older structures often need framing reinforcement before installation; specialist installers; among the most expensive options.
Clay / Concrete Tile
Non-combustible masonry that never fades; excellent in hot climates and a signature look for Mediterranean and Spanish-style homes.
⚠ Heavy enough to require a structural check; tiles can crack under hail or foot traffic; repairs mean matching the exact tile profile.
Architectural Shingle Calculator: What Changes vs. 3-Tab
Flip the shingle type selector to Architectural and this architectural shingle calculator updates coverage per bundle (32.3 vs 33.3 ft²), roof weight, ridge-cap bundles and material cost in one pass. The squares-to-bundles math stays at 3 per square — it is the ~5 lb heavier bundles and the $100–$250 per square pricing that flow straight into your total. No re-measuring, no manual conversion.
Why the Waste Factor Matters
No shingle roof is installed edge-to-edge with zero cuts. Valleys force diagonal cuts, hips and rakes eat partial shingles, and starter courses double the material at the eaves. Ordering exactly the geometric area guarantees a mid-job supply run.
- 10%Simple gable roof — two rectangles, no valleys or dormers.
- 12–15%Hip roofs, one or two valleys, a chimney or skylight.
- 15–20%+Cut-up roofs: dormers, multiple valleys, turrets, steep 10/12+ pitches.
Tip: bundles are always rounded up to full packages — suppliers don't split them — and unopened bundles are usually returnable, so a slight overage is the cheap insurance.
1,200 ft²
Typical 12-square roof needs ~40 bundles with 10% waste
3 bundles
Cover one roofing square with standard 33.3 ft² bundles
1–2 rolls
Synthetic underlayment per 10 squares of roof area
20–33 lin ft
Ridge-cap coverage per bundle along hips & ridges
Beyond the Bundles: the Full Materials Checklist
Field shingles are only the headline item. A complete order includes six more lines — and the calculator outputs every one of them.
Underlayment
Roof area ÷ roll coverage, × layers
Synthetic rolls cover about 1,000 ft²; #15 felt about 400 ft²; #30 felt about 200 ft². Conventional asphalt assemblies between 2:12 and 4:12 require a double layer per IRC — and in snow country, self-adhering ice & water shield at eaves and valleys (~27 lb per 100 ft²) is the norm.
Starter strip
Eave length + rake length ÷ ~105 lin ft per bundle
Factory starter is adhesive-backed and seals the first course against wind uplift. Cut-up 3-tab strips are not a substitute on architectural roofs — the sealant pattern never lines up.
Ridge cap
(Ridge + hip length) ÷ 20–33 lin ft per bundle
Coverage varies by product — 20, 25, 30 or 33 linear feet per bundle. Laminated field shingles do not split cleanly into cap pieces, so order factory hip & ridge bundles separately.
Drip edge
Total eave + rake perimeter ÷ 10 ft sections
Aluminum or galvanized 10-ft sections run along every eave and rake. Order a couple of extra sections — corners and overlaps eat length fast.
Roofing nails
~350 nails per square at 4-nail pattern (~2 lb)
Code minimum is 4 fasteners per strip; high-wind and steep-slope zones require 6. A 3-tab bundle holds about 29 strips, so a square consumes roughly 350 nails — a 50-lb box of 1¼" coil nails covers ~20 squares.
Sealant & flashing
1 tube ≈ 25–30 lin ft of ¼" bead
Walk the roof and total every seam: vent boots, chimney counter-flashing, skylight curbs, sidewall junctions. Buy two extra tubes — a dry tube mid-detail is a real leak risk.
Shingle Weights — New, and Coming Off the Roof
One rule explains most of this table: a bundle is sized to what one person can carry up a ladder — about 70 lb whatever the product. Heavier shingles are split into more bundles, not heavier ones, so a calculator that assumes 3 bundles per square under-orders the exact roofs where it matters most.
| Material | New shingles | Tear-off debris | Notes |
|---|---|---|---|
| 3-tab asphalt | ~200 lb/sq | ~230 lb/sq | The ARMA benchmark single-layer replacement is ~2.5 lb per ft² of roof. |
| Architectural asphalt | ~220 lb/sq | ~300 lb/sq | What sits on most modern homes — the default tear-off scenario. |
| Premium / designer laminate | ~300 lb/sq | ~400 lb/sq | Sold 4–5 bundles per square instead of 3. |
| Wood shake | ~300 lb/sq | ~400 lb/sq | Bulky rather than dense — it fills a dumpster before it maxes the weight. |
| Clay / concrete tile | ~900–1,100 lb/sq | ~950 lb/sq | Masonry — usually banned from mixed C&D dumpsters; needs a dedicated haul. |
| Slate | ~800–1,100+ lb/sq | ~1,170 lb/sq | Never assume a standard roll-off can take it — arrange stone disposal. |
Why tear-off weighs 15–25% more than new
- The underlayment comes off with it — #15 felt actually weighs 7–13 lb per square despite the name.
- Ice & water shield is the heavy one at ~27 lb per 100 ft², and in snow country it can cover a fifth of the deck.
- Nails add a couple of pounds per square, and a roof stripped the morning after rain weighs noticeably more than the same roof in a dry week.
The item that genuinely moves the number is rotten sheathing — if plywood comes off with the shingles, add its weight separately (about 350 lb per cubic yard).
Planning a dumpster for the tear-off?
Multiply the tear-off weight per square by your squares, then by the number of layers coming off — a roof shingled over twice weighs roughly what you would expect that many roofs to weigh. A 15-square, single-layer 3-tab roof lands near 3,450 lb, which already exceeds the 1-ton allowance of a typical 10-yard container. When you are between two sizes, take the larger one and have it on site before the first shingle comes off.
How to Measure a Roof for Shingles
Three ways to get the number — pick by roof complexity and how comfortable you are with a ladder.
From the ground (footprint method)
Measure each side of the home at the eaves — length × width — and add every rectangle together. Multiply the total footprint by the pitch multiplier above. Safest method and accurate for gable and simple hip roofs.
Best for: most homeowners, single-story or accessible lots
Plane by plane (on-roof method)
Measure the length and slope width of every plane and add the areas. Triangular gable ends are ½ × base × height; count dormers and attached garages as their own rectangles. Most accurate — this is how professional takeoffs are done.
Best for: complex roofs, verified quotes, insurance scopes
Aerial & satellite estimates
Imagery tools return footprint and slope lengths in minutes and are fine for ballparking an order. Always verify pitch on site — imagery gets length right but misreads steep-slope corrections more than anything else.
Best for: quick ballpark before the tape measure comes out
Finding the pitch without climbing
Hold a 12-inch level against the shingles at the eave with one end touching the roof, bubble centered. Measure the gap from the roof surface up to the level's 12-inch mark — that gap in inches is your rise over 12, i.e. the x in x/12. A pitch-finder phone app does the same job from a photo of the rake edge. If the building plans are around, they list pitch too.
The footprint method starts at the eaves — measure length × width from outside, then apply the pitch multiplier.
Pro Tips & Common Mistakes
The difference between a smooth order sheet and a mid-job supply run usually comes down to these twelve points.
Tips from the field
Buy one extra bundle per ~10 squares
An extra bundle or two costs $30–$80 and saves a mid-job supply run. Most suppliers accept unopened bundles back within 30–90 days, so the downside is a refund trip, not a loss.
Match dye lots on big orders
On jobs needing 60+ bundles, get them from the same production run. Different lots can shade noticeably — especially on architectural lines — and the difference shows up on the roof, not in the driveway.
Store bundles flat, on a pallet
Stacking shingles on edge warps them before installation day. Keep bundles flat, covered from direct sun, and never leave them draped over a ridge or on uneven ground.
Order nails by the box, not loose
A 50-lb box of 1¼" coil roofing nails runs $80–$120 and covers about 20 squares. Buying by the pound costs more per nail and leaves you short on steep-slope jobs.
Plan ~2 labor hours per square
A crew of 3–4 installs a 20–25 square gable roof in 1–2 days; add a day for tear-off and more for 8/12+ pitches. Divide total labor hours by crew size for realistic on-site time.
Schedule the dumpster before tear-off
Tear-off debris arrives all at once with nowhere to go. Have the container on site the morning the crew starts, and size it by weight — shingle debris maxes weight long before it fills volume.
Mistakes that cost real money
Skipping the pitch multiplier
A 6/12 pitch adds 11.8% to the footprint; 12/12 adds 41.4%. Forget it and you are short exactly that share of materials — 6+ bundles on a 20-square roof.
Measuring the attic floor
Inside measurements give you the flat footprint, not the sloped surface. Measure outside at the eaves, or apply the multiplier — never both halves and expect it to cancel out.
Using one waste % for every roof
10% belongs on a clean gable. Hips, valleys, dormers and skylights push the real number to 15–20%. Match the allowance to the geometry, not to habit.
Assuming every bundle covers 33.3 ft²
Product lines ship at 20, 25, 32.3 and 33.3 ft² per bundle. The wrapper is the authority — a calculator set to the wrong coverage under-orders the heaviest roofs first.
Cutting field shingles into ridge cap
Works on 3-tab; fails on laminates, whose bonded layers will not separate cleanly. Factory hip & ridge units are engineered for the bend and the wind rating.
Re-covering over two layers
Most codes cap asphalt roofs at two total layers. Re-covering saves $100–$150/sq in tear-off labor, but it hides deck rot and adds weight — inspect for soft spots first, and tear off if you find any.
Shingle Calculator for Hip, Gable & Shed Roofs
Roof shape changes the waste factor, the ridge-cap count and how you measure — not the core math. Enter your footprint and pitch above, then pick the waste preset that matches your roof type below.
Hip Roof Shingle Calculator
Four sloped planes, no vertical ends, and every edge is either a hip or a valley. A shingle calculator for hip roof geometry should run 12–15% waste, because hips and valleys force diagonal cuts on nearly every course. Hip length also drives ridge-cap bundles — the tool estimates it from your footprint and pitch automatically.
Gable Roof Shingle Calculator
Two rectangles, two slopes, straight rakes — the friendliest layout there is. A shingle calculator for gable roof projects can run a lean 10% waste: full courses, few cuts, and offcuts from one side often start the opposite rake. Double the footprint for the two planes and let the pitch multiplier do the rest.
Shed Roof Shingle Calculator
One single-slope plane makes this the simplest estimate of all: length × width × pitch multiplier, no valleys, no hips. A shed roof shingle calculator run can stay near 5–10% waste, and many shed builds start every course from one eave line. Enter the footprint once — extra sections are only needed for L-shaped sheds.
Shingle Calculator FAQ
How many shingles are in a bundle?+
A standard 3-tab bundle contains 29 shingles sized 12" × 36" and covers about 33.3 ft² of roof. Architectural bundles usually carry around 21–26 larger laminated strips at roughly 32.3 ft², while heavy designer lines can ship 4–5 bundles per square. Always confirm against the coverage printed on the wrapper.
How many bundles of shingles do I need for a 1,200 sq ft roof?+
Convert the surface to squares (1,200 ft² ÷ 100 = 12 squares), add your waste factor (12 squares × 1.10 ≈ 13.2 squares), then multiply by 3 bundles per square — about 40 bundles of 3-tab or architectural shingles. Enter your exact pitch and footprint above and the calculator does this, including rounding up to full bundles.
What is a 'square' in roofing?+
A square is the roofing industry's unit of area: exactly 100 square feet of roof surface. Suppliers price shingles, underlayment, labor and dumpsters per square, so every estimate on this page rolls up to squares before converting to bundles.
How much waste factor should I add?+
About 10% for a simple gable roof, 12% for roofs with some hips and valleys, and 15% or more for complex roofs with dormers, skylights and many diagonal cuts — guidance consistent with NRCA estimating practice. Drag the waste slider to see the bundle count update instantly.
Does the calculator include underlayment and ridge caps?+
Yes. Alongside field shingles you get underlayment rolls (synthetic, #15 or #30 felt, one or two layers) and ridge-cap bundles from your hip & ridge length, plus a planning-grade roofing-nail count based on 4 or 6 nails per shingle.
How do I measure my roof for shingles?+
Measure the length and width of each roof plane at the eaves — horizontally, not along the slope. Choose the pitch that matches your roof (or enter the angle or percent grade). If the roof has more than one rectangle, add another section in the calculator and the areas sum automatically.
How is the roof pitch multiplier calculated?+
The multiplier is √(1 + (rise/12)²). It converts horizontal footprint area to true sloped roof area. A 6/12 pitch multiplies the footprint by 1.118 (+11.8%), while a 12/12 pitch multiplies it by 1.414 (+41.4%).
How accurate is the labor cost estimate?+
The labor estimate uses per-square installed rates typical for your zip-code region, so it is a planning budget rather than a quote. Actual prices vary with roof complexity, story height, tear-off condition, season and contractor overhead — treat the ±10% range as a starting point for negotiations.
Can I install new shingles over an existing layer?+
Most residential codes allow up to two total layers of asphalt shingles. Re-covering skips the $100–$150 per square tear-off labor, but it adds weight, hides deck damage and can void the manufacturer warranty. If the inspection finds soft spots, curling or water stains, tear off to the deck.
How much does a bundle of shingles weigh?+
About 65–75 lb — and that holds for almost every asphalt product, because bundles are sized to what one person can carry up a ladder. Heavier shingles are split into more bundles (4–5 per square) rather than heavier ones. Use the wrapper weight for delivery planning.
How much does a square of shingles weigh?+
New material runs about 200 lb per square for 3-tab and 220 lb for architectural, rising to 300 lb for premium laminates. Coming off the roof it is heavier — roughly 230–400 lb per square — because the tear-off carries the felt, nails and any moisture the old shingles absorbed.
How long does it take to shingle a roof?+
A crew of 3–4 experienced roofers completes a 20–25 square gable roof in 1–2 days, plus a day of tear-off if needed. Complex layouts with hips, valleys and dormers, or pitches of 8/12 and steeper, can run 3–4 days. Plan on roughly 2 labor hours per square.
How many roofing nails do I need?+
Code minimum is 4 nails per strip shingle, and 6 in high-wind or steep-slope zones. That works out to roughly 350 nails (about 2 lb) per square at the 4-nail pattern — a 50-lb box of coil nails covers about 20 squares. The calculator outputs a nail count with your bundle total.
What size dumpster do I need for a tear-off?+
Weight drives the answer, not volume. A single layer of 3-tab on a 15-square roof lands around 3,450 lb — over the 1-ton allowance of a typical 10-yard rental — while three layers of architectural can double that. Count every layer coming off and size up when you are between two containers.
What is the difference between footprint area and roof area?+
Footprint area is the flat ground the home covers; roof area is the actual sloped surface and is always larger. The gap is the pitch multiplier — 5.4% at 4/12, 11.8% at 6/12, 41.4% at 12/12. Ordering off the footprint without the correction is the most common (and most expensive) DIY mistake.
How much do shingles cost per bundle in 2026?+
Expect roughly $25–$65 per bundle for 3-tab, $35–$85 for architectural and $65–$150 for premium designer lines — which works out to about $80–$200, $100–$250 and $250–$600 per square. Most suppliers offer a price break at 30+ squares, so bundling orders across jobs pays.
Is there a roof shingle calculator app I can use on my phone?+
Yes — this page is a free roof shingle calculator app that runs in any mobile browser with nothing to download. It is a web app: add it to your phone's home screen and it works like an installed app, with the same bundle, square, nail and cost outputs as on desktop. Inputs are touch-friendly and every estimate updates as you type.
Does the shingle calculator work in square feet or squares?+
Both. Enter footprint dimensions in plain square feet — a 40 ft × 30 ft rectangle is 1,200 sq ft — and the pitch multiplier converts that to true sloped roof area, then to squares (1 square = 100 sq ft) and bundles. Treat it as a roof shingle calculator: square feet of footprint in, squares and bundles out. Because it works from square feet of footprint rather than tape measurements taken on the slope, it is the method most DIY measuring guides recommend for multi-section roofs.
How does an architectural shingle calculator differ from a 3-tab estimate?+
The core math is the same — squares × 3 bundles — but an architectural shingle calculator tracks the slightly lower coverage per bundle (32.3 vs 33.3 ft²), the ~5 lb heavier bundles, the higher material cost ($100–$250 vs $80–$200 per square) and heavier ridge-cap bundles. Switch the shingle type selector to Architectural above and every one of those outputs recalculates at once.
Shingle & Roofing Glossary
The vocabulary contractors use — so the quote, the order and this calculator all speak the same language.
Footprint area
The flat, ground-level area the roof covers — length × width at the eaves, before any slope correction.
Roof pitch
Rise over a 12-inch run. A 6/12 roof climbs 6 inches for every horizontal foot.
Pitch multiplier
√(1 + (rise/12)²) — converts flat footprint to true sloped area. 6/12 = 1.118, 12/12 = 1.414.
Roofing square
100 ft² of roof surface — the unit suppliers price shingles, felt, labor and dumpsters in.
Bundle
The package shingles are sold in; sized so one person can carry it up a ladder (~65–75 lb whatever the product).
Waste factor
Extra material for cut-offs at valleys, hips, rakes and penetrations — 10% simple gables, up to 20% cut-up roofs.
Starter strip
Adhesive-backed first course along eaves and rakes that seals against wind uplift. ~105 linear feet per bundle.
Ice & water shield
Self-adhering membrane at eaves and valleys in cold climates; ~27 lb per 100 ft², heavier than felt.
Drip edge
Metal flashing along eaves and rakes that directs runoff into the gutters; sold in 10-ft sections.
Tear-off
Stripping the old roof down to the deck. Adds a day of labor and debris weight — but reveals hidden rot.
Bundle Counts by Roof Size
Quick reference — 33.3 ft² bundles, 10% waste, before pitch correction. Add the pitch multiplier for your roof.
1,000 ft² roof
33 bundles
10 squares
1,500 ft² roof
50 bundles
15 squares
2,000 ft² roof
66 bundles
20 squares
2,400 ft² roof
80 bundles
24 squares
= area ÷ 33.3, rounded up, +10% waste. For pitch correction use the calculator above.
| Footprint | Pitch | Squares (incl. pitch + 10% waste) | Bundles (rounded up) |
|---|---|---|---|
| 24 × 30 ft (720 ft²) | 4/12 | 8.3 | 26 |
| 30 × 40 ft (1,200 ft²) | 6/12 | 14.8 | 45 |
| 30 × 50 ft (1,500 ft²) | 6/12 | 18.4 | 56 |
| 40 × 60 ft (2,400 ft²) | 8/12 | 31.7 | 96 |
| 40 × 60 ft (2,400 ft²) | 12/12 | 37.3 | 112 |
Common footprints at their typical pitches, using 3 bundles per square. Notice how the same 2,400 ft² house needs 16 more bundles at 12/12 than at 8/12.
Roofing Guides & Tools
Deep-dive measuring methods, waste rules and cost breakdowns — or browse the full collection of free calculators.