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Roofing Square Calculator

Convert building footprint and pitch into roofing squares and asphalt shingle bundles — with waste for simple or cut-up roofs.

Roof size & pitch

Roofing squares to order

22.1

squares incl. 10% waste · 67 bundles

Pitch
6/12 · ×1.118
Roof area
2,012 sq ft
Squares (raw)
20.12
With waste
22.14 sq

Asphalt bundles

67

3 bundles per square × 22.14 sq → order whole bundles. Metal and tile are sold differently — use squares for those quotes.

Breakdown

  1. Footprint × multiplier = 2,012 sq ft roof
  2. ÷ 100 = 20.12 squares
  3. + waste → 22.14 squares / 67 bundles

Price data updated . National US ranges from published supplier and contractor averages. Not a bid. Local quotes vary.

How roofing squares are calculated

Contractors quote materials in squares. Footprint alone understates the job — pitch stretches the surface. Waste covers cut-offs at hips, valleys, and eaves.

roof_area   = footprint_sq_ft × pitch_multiplier
squares     = roof_area ÷ 100
order_sq    = squares × (1 + waste %)
bundles     = order_sq × 3          (typical asphalt)

Worked example. An 1,800 sq ft footprint at 6/12 (multiplier 1.118) is 2,012 sq ft of roof → 20.1 squares. With 10% waste you plan 22.1 squares ≈ 67 bundles at 3 per square.

Footprint to squares chart (no waste)

Quick lookup from common house footprints and pitches. Add 10–15% waste before you order. Multipliers match our roof pitch calculator.

Footprint4/126/128/1212/12
1,000 sq ft10.511.212.014.1
1,500 sq ft15.816.818.021.2
1,800 sq ft19.020.121.625.5
2,000 sq ft21.122.424.028.3
2,500 sq ft26.428.030.135.4
3,000 sq ft31.633.536.142.4
  • One roofing square = 100 sq ft of roof surface (not footprint).
  • Most asphalt shingles ship 3 bundles per square; some premium lines use 4 — check the wrapper.
  • Order by whole bundles; leftover starter/ridge packs are sold separately.

Roofing square calculator FAQ

What is a roofing square?
One roofing square is 100 square feet of roof surface area — the unit contractors and suppliers use to price shingles, underlayment, and tear-off. It is not the same as your building’s footprint square footage.
How do I convert square feet to roofing squares?
Multiply footprint by the pitch area multiplier to get roof surface sq ft, then divide by 100. Example: 1,800 sq ft footprint at 6/12 (×1.118) ≈ 2,012 sq ft of roof → about 20.1 squares before waste.
How much extra should I order?
Plan 10% waste on a simple gable. Use about 15% when the roof has valleys, dormers, hips, or many cuts. Always round up to whole bundles — leftover partial bundles are hard to return once opened.
How many bundles are in a square?
Most 3-tab and architectural asphalt shingles are three bundles per square. Some thicker laminates ship four — read the bundle label. This calculator assumes three, which matches the majority of US residential asphalt products.
Does this include ridge, starter, or underlayment?
No. Squares and field-shingle bundles cover the main roof planes. Starter strip, hip/ridge caps, ice-and-water shield, and underlayment are separate line items — estimate those after you know squares, then price the job in the roofing cost calculator.
Can I use this for metal or tile?
Use the square count for any material — that is the common quoting unit. Bundle counts apply to asphalt only. Metal and tile are ordered by panels, squares, or pieces per the manufacturer’s coverage chart.

Next: price the roof

Now estimate what this will cost → · Check pitch & multiplier · All roofing calculators