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Roofing Shingles Calculator

Roof area converted to roofing squares, then to bundles at the standard 3-per-square rate.

Roof area (sq ft)

Waste factor (%)

Bundles needed

Standard 3-tab shingles use 3 bundles per 100 sq ft 'square' — architectural shingles sometimes use 4.

Roofing squares: 22

What you entered

Roof area (sq ft): 2000Waste factor (%): 10

1
Roof area with 10% waste
2000 × 1.10= 2200 sq ft
2
Convert to roofing squares (1 square = 100 sq ft)
2200 ÷ 100= 22 squares
3
Bundles (3 bundles per square is standard)
22 × 3= 66 bundles

Result

Bundles needed: 66

A 2000 sq ft roof needs about 66 bundles of shingles (22 roofing squares).

Shingle bundles for common roof areas at 3 bundles per roofing square

Roof area here is the actual sloped surface, not the building footprint. Each row adds the waste allowance, converts to roofing squares of 100 sq ft, then multiplies by the standard 3 bundles per square and rounds up, exactly as the calculator does.

Roof area (sq ft)	Roofing squares at 10% waste	Bundles at 10% waste	Bundles at 15% waste
1,000	11.0	33	35
1,200	13.2	40	42
1,500	16.5	50	52
1,800	19.8	60	63
2,000	22.0	66	69
2,400	26.4	80	83
2,800	30.8	93	97
3,200	35.2	106	111
4,000	44.0	132	138

Enter the sloped roof area, not the footprint. A footprint becomes roof area when multiplied by the slope factor for the pitch, about 1.118 at 6:12 and 1.202 at 8:12, so a 2,000 sq ft footprint on a 6:12 roof is roughly 2,236 sq ft of roof. Some architectural shingles cover 4 bundles per square instead of 3, in which case multiply these counts by 4/3 and check the wrapper. Starter strip, ridge cap, underlayment, drip edge and nails are all separate line items. Use 15 percent waste on a roof with hips, valleys, dormers or several penetrations. Roof work is a fall risk and a bundle weighs 60 to 80 lb: steep or high roofs are a job for a licensed roofer.

What a 'square' means in roofing

Roofers measure in 'squares' — one square covers 100 square feet of roof. Standard 3-tab shingles use 3 bundles per square; some architectural shingles use 4 bundles per square, so check your specific product.

Roof area isn't the same as footprint

A sloped roof's actual surface area is larger than the home's footprint — this calculator expects the actual roof surface area (accounting for pitch), not the ground-level building footprint.

Frequently asked questions

My roof is 2,000 sq ft — how many bundles of shingles do I need?

About 60 bundles plus waste. 2,000 sq ft = 20 roofing squares, at 3 bundles per square = 60 bundles. Add 10-15% for waste, ridge caps, and starter strips — order about 66-69 bundles.

What's a 'roofing square'?

One roofing square covers 100 square feet of roof. It's the standard unit roofers use for estimating. A 2,000 sq ft roof = 20 squares. Most shingle brands package 3 bundles per square for 3-tab shingles.

Do architectural shingles need more bundles per square?

Sometimes — some architectural (dimensional) shingle brands require 4 bundles per square instead of 3. Check the specific product's coverage per bundle before ordering. Architectural shingles are thicker and heavier than 3-tab.

How do I calculate my actual roof area from the footprint?

Multiply the footprint area by the roof pitch multiplier. For a 6:12 pitch, multiply by 1.118. For 8:12, multiply by 1.202. For 12:12, multiply by 1.414. Use the roof pitch calculator to find your pitch first.