Use this free roofing calculator to estimate roof area, roofing squares, and shingle bundles for a simple pitched roof before you check the real roof and product label.
1200 ft2 footprint, 6/12 pitch
This is a rough planning number. Product wrapper coverage, ridge cap, starter strips, low-slope rules, safe access, and contractor measurement can change the real order.
Estimate roof squares for a simple footprint.
Adjust for roof pitch and waste.
Estimate shingle bundles at 3 bundles per square.
Prepare a rough number before contractor measurement.
14.76 squares, 45 bundles
8.16 squares, 25 bundles
21.23 squares, 64 bundles
Need a slower walkthrough, a related calculator, or the full library? These links keep you close to the task you started.
Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.
Use it when your task matches one of these common needs: Estimate roof squares for a simple footprint. Adjust for roof pitch and waste. It works best when you already know simple footprint length, footprint width, pitch rise per 12, and waste percent.
In plain language: The calculator multiplies footprint area by a pitch factor, adds waste, divides by 100 square feet per roofing square, and estimates 3 bundles per square. The examples on the page are there so you can compare your inputs with a roofing material example before copying the answer.
Footprint length and width: The flat building footprint, not the house square footage and not the sloped roof surface. Pitch rise per 12: How many inches the roof rises for every 12 inches of horizontal run. A 6/12 roof rises 6 inches over 12 inches. Waste percent: Extra roofing for cuts, starter strips, ridge cap, hips, valleys, overhangs, and mistakes.
Read the headline estimate first, then check the material, waste, coverage, and unit lines. For project tools, the supporting lines are often the difference between a rough idea and a list you can actually shop from.
Complex roofs, valleys, hips, dormers, openings, starter strips, ridge cap, product coverage, low-slope rules, and local installation practices can change material needs. Check the roof shape, pitch, shingle wrapper, manufacturer instructions, local code, and safe access before ordering materials.
One roofing square is 100 square feet of roof surface. If the calculator shows 14.76 squares, that means about 1,476 square feet after pitch and waste.
No. Three bundles per square is common for many asphalt shingles, but heavier or specialty products can be different. Check the wrapper or manufacturer sheet before buying.
Not exactly. The waste percent can help cover cuts and small extras, but starter strips, ridge cap, ridge vent, flashing, underlayment, nails, and drip edge often need separate planning.
Use extra caution. Low-slope roofs can need special underlayment or different roofing materials. Check the shingle instructions, local code, and a roofer before ordering.
Do not climb onto a roof just to use this calculator. Use ground measurements, plans, a safe measurement report, or a professional if roof access is not clearly safe.
No. The roofing estimate runs in your browser tab. Do not enter your address or any private job details.