Roof Square Calculator

Enter the building size and pitch to get the roof area in square feet and in roofing squares. Already know the area? Switch to roof area and add your extra.

Roof squares

14.1 squares

1,409 sq ft (130.9 m²) · 15.5 with 10% extra

14.1 roof squares is 1,409 sq ft of roof surface. Order 15.5 squares with 10% extra.

Roof area1,409 sq ft (130.9 m²)
Footprint with overhang1,260 sq ft (117.1 m²)
Pitch multiplier1.118
Squares with extra15.50
Area with extra1,550 sq ft (144.0 m²)
At your price per squareAdd a price

One roofing square is 100 square feet of roof surface. The area is the sloped surface, not the footprint.

Planning estimate, not a quote. Disclaimer

What is a roofing square?

A square is 100 square feet of roof surface. Roofers measure, price and order shingles by the square, so a 2,000 sq ft roof is 20 squares. The surface of a sloped roof is bigger than the floor plan beneath it, which is why you measure the roof, or calculate it from the footprint and pitch as this page does.

Roof area = (length + 2 × overhang) × (width + 2 × overhang) × multiplier
Squares = roof area ÷ 100
Order = squares × (1 + extra %)

Example: A 40 × 28 ft house with 12-inch overhangs and a 6/12 roof: footprint with overhang 42 × 30 = 1,260 sq ft, × 1.118 = 1,409 sq ft of roof, or 14.1 squares. With 10% extra that is 15.5 squares and 47 bundles.

Roof area by footprint and pitch

A quick check with no overhang: multiply the footprint by the factor for your pitch.

Roof area for a 1,000 sq ft footprint
Pitch	Multiplier	Roof area	Squares
3/12	1.031	1,031 sq ft	10.31
4/12	1.054	1,054 sq ft	10.54
5/12	1.083	1,083 sq ft	10.83
6/12	1.118	1,118 sq ft	11.18
7/12	1.158	1,158 sq ft	11.58
8/12	1.202	1,202 sq ft	12.02
9/12	1.250	1,250 sq ft	12.50
10/12	1.302	1,302 sq ft	13.02
12/12	1.414	1,414 sq ft	14.14

Gable or hip

With the same footprint, overhang and pitch, a gable roof and a hip roof have the same surface area. They differ in the ridge and hip length, which affects ridge cap and waste. See the hip roof calculator. Complex roofs, with dormers, valleys and several planes, should be measured plane by plane and added up.

Frequently asked questions

How do I calculate roof square footage?

Multiply the footprint (with overhang) by the pitch multiplier. A 1,000 sq ft footprint at 6/12 is 1,118 sq ft of roof.

How many squares is a 2,000 sq ft roof?

20 squares, because one square is 100 sq ft. With 10% extra you would order 22 squares.

How many squares is a 1,500 sq ft house?

It depends on the pitch. A 1,500 sq ft footprint at 6/12 is 1,677 sq ft of roof, which is 16.8 squares, before the overhang.

Does a steeper roof cost more?

It has more surface, so it needs more material. A 12/12 roof has 34% more area than a 4/12 roof on the same footprint, before any change in labor.

How many bundles of shingles are in a square?

Three for most asphalt shingles. Use the shingle calculator for bundles, starter and ridge cap.

Other roofing calculators

Sources

GAF: How many bundles of shingles are in a square? (checked Nov 12, 2026)