Roofing square calculator: squares, bundles and waste
A roofing square is 100 square feet of roof. To find the squares on a simple roof, multiply the footprint by the pitch multiplier, add waste, and divide by 100. This calculator does that and converts the answer to shingle bundles. For a cut-up roof, use a measurement report and treat this as a sanity check.
On this page
Squares to order18.8
- Bundles
- 57
- Roof area before waste
- 1,677 sq ft
- Pitch multiplier
- 1.118
- Material estimate
- $2,630
Runs in your browser. Nothing you type is sent or saved. The result is an estimate from your own inputs, not a quote.
How the roofing square calculator works
A roof is bigger than the floor under it, because it slopes. The pitch multiplier turns flat area into sloped area:
- Pitch multiplier = the square root of (1 + (rise / 12) squared). A 6/12 roof is 1.118.
- Roof area = length x width x pitch multiplier.
- Squares = roof area x (1 + waste) / 100.
- Bundles = squares x bundles per square, rounded up.
Most three-tab and architectural shingles come three bundles to the square, but heavier lines can take four or more. The wrapper is the source to trust.
How much waste to add
| Roof shape | Common starting point |
|---|---|
| Simple gable, few penetrations | About 10% |
| Hip roof | About 12 to 15% |
| Cut-up roof with valleys and dormers | 15% or more |
These are starting points many roofers use, not rules. Your own waste on past jobs is a better number. Starter, ridge caps, underlayment, drip edge and ice and water are separate line items: see the full roofing estimate template.
From squares to an order
Once the measurement report is in, Alvin can turn it into a priced material order on your supplier's site and hold the cart for your approval, so nothing is bought until you say so. See roofing material orders from measurement reports.
Frequently asked questions
How many bundles of shingles are in a square?
Usually three for standard architectural and three-tab shingles. Some heavier or designer lines take four or five bundles per square. Check the coverage printed on the wrapper for the product you are ordering.
How do I calculate roofing squares from square footage?
Divide the roof's surface area in square feet by 100. A 2,000 square foot roof surface is 20 squares before waste. Use the sloped roof area, not the floor area of the house.
Does this roofing calculator work for hip roofs?
It gives a close area for a simple hip roof if every side has the same pitch, because the pitch multiplier applies to the whole footprint. Add more waste for the hip and ridge cuts. For anything cut up, order a measurement report.
The math is the easy part. Alvin does the office work after it.
Alvin is the personal assistant for home services businesses. Your team asks in the app or forwards an email, and Alvin does the work across QuickBooks, your CRM and your suppliers. Anything that spends money or goes to a customer waits for your approval.