Roof Shingle Calculator
Work out how many bundles of shingles your roof needs. Enter the house size, overhang and roof pitch, pick a gable or hip roof and a shingle type, and get roof area, squares, bundles, starter strip, ridge cap, underlayment, ice & water shield, drip edge, nails and cost — with a pitch check, a roof plan, comparison tables and a downloadable PDF.
| Pitch | Factor | Roof area | Squares | Bundles | Underlayment |
|---|---|---|---|---|---|
| Enter the house size and pitch to compare | |||||
| Shingle | Per square | Bundles | Weight | Nails | Est. cost |
|---|---|---|---|---|---|
| Enter the house size and pitch to compare | |||||
How to use the roof shingle calculator
Four quick steps turn your house size and pitch into roof area, squares, shingle bundles and every accessory — starter strip, ridge cap, underlayment, ice barrier, drip edge and nails — with a pitch check, a roof plan, by-pitch and by-type tables, a chart and a downloadable report.
Enter the roof size
Give the house length, width and overhang — or drop in a known roof area from a roof report.
Set pitch & style
Enter the roof pitch and choose a gable or hip roof — the slope factor is applied for you.
Pick shingles & waste
Choose 3-tab, architectural or premium, a waste allowance and your price per bundle.
Read results & save a PDF
Get bundles, squares, accessories, nails, tear-off weight and cost, then download a report.
How shingle quantities are calculated
It all starts from the roof area. The pitch turns your flat footprint into the real sloped surface through a slope factor, then squares and bundles follow. Here is the exact math the calculator runs.
Worked example — 50 × 30 ft house, 12″ overhang, 6/12 pitch, gable, architectural shingles, 10% waste
Footprint: 52 × 32 = 1,664 sq ft · Slope factor: √(1 + 0.5²) = 1.12
Roof area: 1,664 × 1.12 ≈ 1,860 sq ft · Squares: 18.6 → +10% = 20.5
Bundles: 20.5 × 3 ≈ 62 · At $42/bundle: ≈ $2,600
≈ 1,860 sq ft of roof — about 20.5 squares with 10% waste, or roughly 62 bundles of architectural shingles plus starter, ridge cap and underlayment.
Roof shingle reference charts
Handy lookups for how pitch and shingle type change the roof area, squares, bundles and cost.
| Pitch | Slope factor | Roof area | Squares (+10%) | Bundles | Shingles |
|---|---|---|---|---|---|
| 3/12 | 1.031 | 1,715 sq ft | 18.9 | 57 | 2 layers underlay |
| 4/12 | 1.054 | 1,754 sq ft | 19.3 | 58 | OK |
| 6/12 | 1.118 | 1,860 sq ft | 20.5 | 62 | OK |
| 8/12 | 1.202 | 2,000 sq ft | 22.0 | 66 | OK |
| 10/12 | 1.302 | 2,166 sq ft | 23.8 | 72 | OK |
| 12/12 | 1.414 | 2,353 sq ft | 25.9 | 78 | OK |
Same footprint, more pitch, more roof: a 12/12 roof needs about a third more shingles than a 3/12 roof. Below 4/12, asphalt shingles need a double layer of underlayment.
| Shingle | Per square | Bundles | Weight | Look | Est. cost |
|---|---|---|---|---|---|
| 3-tab | 3 | 62 | 230 lb/sq | Flat, budget | ~$1,980 @ $32 |
| Architectural | 3 | 62 | 320 lb/sq | Dimensional | ~$2,600 @ $42 |
| Premium | 4 | 82 | 420 lb/sq | Slate / shake look | ~$5,740 @ $70 |
3-tab and architectural both run 3 bundles per square, so the bundle count matches — the difference is weight, looks and price. Premium designer shingles take 4 bundles per square. Prices are placeholders; use your local quote.
| Roof | Waste | Why |
|---|---|---|
| Simple gable | 10% | Straight runs, few cuts |
| Hip roof | 15% | Angled cuts on four sides |
| Valleys & dormers | 20% | Lots of cutting and waste |
Waste covers starter rows, cut-offs and mistakes. Cut-up roofs eat more material, so round the waste up rather than down.
What the shingle calculator gives you
House size, pitch and shingle type give you a full roofing materials list, not just a bundle count.
Roof shingles at a glance
Who uses a roof shingle calculator
From a DIY re-roof to a contractor’s quote, the same calculator sizes the shingles and every accessory.
Re-shingling their own house and wants an honest bundle count plus starter, cap, underlayment and nails.
- Measure the footprint
- Set the pitch
- Add 10–15% waste
Comparing roofer bids and wants to know roughly how many squares and bundles the job really needs.
- Enter house size
- Check the squares
- Compare to the bid
Pricing a job fast and needs squares, bundles, accessories, tear-off weight and a material cost.
- Drop in the roof area
- Pick the shingle type
- Set tear-off layers
Tips for ordering roof shingles
A clean shingle order comes from the right area, the right waste and not forgetting the accessories.
Roof shingle calculator FAQ
Quick answers about bundles, squares, roof area, pitch, waste and the extras.
Work out the sloped roof area, divide by 100 to get squares, add a waste allowance, then multiply by the bundles per square (3 for 3-tab and architectural, 4 for premium).
A 50 × 30 ft house at a 6/12 pitch is about 1,860 sq ft, or 20.5 squares with 10% waste — roughly 62 bundles of architectural shingles.
Most 3-tab and architectural shingles come 3 bundles to a square (100 sq ft). Heavy premium or designer shingles usually take 4 bundles per square.
Always check the wrapper of the exact product, since coverage varies by brand.
Multiply the footprint (length plus overhang × width plus overhang) by the slope factor, which is √(1 + (pitch÷12)²).
A 52 × 32 ft footprint is 1,664 sq ft; at a 6/12 pitch the slope factor is about 1.12, so the roof area is about 1,860 sq ft.
A roofing square is 100 square feet of roof surface. Roofers price and order shingles, underlayment and labor by the square.
A 2,000 sq ft roof is 20 squares.
Steeper roofs have more surface for the same footprint. On a 50 × 30 ft house the roof grows from about 18.9 squares at 3/12 to 20.5 at 6/12 and 25.9 at 12/12.
So a 12/12 roof needs roughly a third more shingles than a low 3/12 roof of the same footprint.
Asphalt shingles need a pitch of 2/12 or steeper. From 2/12 up to 4/12 they must go over two layers of underlayment.
Below 2/12 you need a low-slope system such as a membrane or standing-seam metal instead.
About 10% for a simple gable roof, 15% for a hip roof, and up to 20% for roofs with lots of valleys, dormers or angles.
The waste covers starter rows, cutting and mistakes.
Yes. Starter strip runs along the eaves and rakes (about 105 ft per bundle) and ridge cap covers the ridges and hips (about 25 ft per bundle).
They’re separate from the field shingles, so add them to the bundle count rather than cutting them from the main shingles.
Estimate only — confirm with your supplier. This calculator works in US units; 1 roofing square = 100 sq ft, and roof area = footprint × √(1 + (pitch÷12)²). It uses typical coverage — 3 bundles per square for 3-tab and architectural, 4 for premium, starter at about 105 ft per bundle, ridge cap at about 25 ft per bundle and underlayment at 1,000 sq ft per roll — so check the wrapper of the product you buy. Asphalt shingles need a 2/12 pitch or steeper, with double underlayment below 4/12. Prices are placeholders; enter your local price. Ice-barrier, nailing and underlayment rules come from your local building code and the shingle maker’s instructions.