free tool

Free Roofing Calculator

Plan squares, waste, underlayment, and ridge straight from your field measurements. Set your own waste percentage and planning ranges. It is a planning worksheet for contractors, not a bid.

Worksheet inputs

Mode

Footprint length (ft)

Footprint width (ft)

Roof pitch

Material

Complexity / waste preset

Few cuts; low scrap.

Waste %

Material qty assumptions

Include underlayment rollsAssumption: 4 squares per roll, rounded up.Include ridge (lf): enter length; not estimated from footprintInclude starter (lf): enter length; not estimated from footprint

Show optional planning dollar rangeRegional planning rates you can edit. Never a bid.

Planning region

Coarse market seed only. No street, ZIP, or address lookup.

Planning low ($/sqft)

Planning high ($/sqft)

Planning range. Not a bid. Final pricing after on-site inspection.

Architectural asphalt (national planning avg). As of July 2026. Public national planning averages. Edit for your market.

Results

Enter the footprint or known squares, then calculate. Results appear here with no email gate.

How it works

Enter your roof
Enter a footprint length and width, or the squares you already know, and pick the roof pitch.
Set waste and materials
Choose a waste percentage and shingle material. Add underlayment, ridge, and starter if you want them counted.
Read your squares and materials
The worksheet returns pitch-corrected squares, bundle and material quantities, and an editable planning range you can print or save as a PDF.

How this calculator works

What is a roofing square?

One roofing square equals 100 square feet of roof surface after pitch correction and waste are applied as shown in Results.

How does pitch change area?

Horizontal footprint is multiplied by a published pitch correction factor for the selected rise/12. Example: 6/12 to 1.118.

Pitch rise over 12 and correction factors
Rise / 12	Factor
0/12	1.000
1/12	1.003
2/12	1.014
3/12	1.031
4/12	1.054
5/12	1.083
6/12	1.118
7/12	1.158
8/12	1.202
9/12	1.250
10/12	1.302
11/12	1.357
12/12	1.414

When is waste applied?

Waste percent is applied after the pitch factor: scrap planning on the corrected roof area, not on the flat footprint alone.

Where do planning $/sqft rates come from?

Public national planning averages. Edit for your market. As of July 2026. Choosing a planning region applies a labeled regional offset to those national averages, not a local market survey. Always editable, never a bid.

Is this a bid or a contract price?

No. This is a planning worksheet only. Final pricing is after on-site inspection.

Who is this for?

Roofing contractors and estimators planning residential and commercial pitched jobs. Planning worksheet only. Not a homeowner roof-replacement cost tool.

Does this cover flat or commercial membrane roofs?

No. This calculator is for pitched roofs (footprint and pitch, or known squares). It is not a TPO, EPDM, or low-slope membrane takeoff.