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✓ 1 Square = 100 Sq Ft = 3 Bundles

Roof Shingle & Square Calculator

Convert ground footprint and pitch into actual slope area, shingle bundles, starter strips, and ridge caps.

House Footprint & Pitch

Along the ridge / eave line
Ridge to eave (horizontal run)
Roof Material Order Estimate
Shingle Bundles 43 Bundles 3 Bundles / Square
Roofing Squares 14.2 Sq 100 sq ft = 1 Square
Actual True Roof Area: 1,420 sq ft
Starter Strip (Eaves): 92 Linear Ft
Ridge / Hip Cap Shingles: 2 Bundles
Synthetic Underlayment (10-Sq Rolls): 2 Rolls

Frequently Asked Questions

How many bundles of shingles are in 1 roofing square?

One roofing square equals 100 square feet. For standard architectural and 3-tab asphalt shingles, there are exactly 3 bundles per square. (Special heavyweight luxury shingles may require 4 or 5 bundles per square).

How do you calculate roof shingles from ground footprint?

Measure the length and width of your house footprint, add twice the eave/rake overhang to each dimension, multiply by the roof pitch multiplier (e.g. 1.118 for a 6:12 pitch) to find true roof surface area, add 10% to 15% for waste and valleys, divide by 100 to get Squares, and multiply Squares by 3 to get Bundles.

How much underlayment do I need?

Synthetic roof underlayment typically comes in 10-square rolls (1,000 sq ft). Divide your total roof squares by 10 and round up to the nearest whole roll.