QuikCalcTools
Roofing units · Step 3

Roofing Squares Calculator

Convert roof square footage to roofing squares and add a visible waste allowance. One roofing square equals 100 square feet.

  • Square feet to squares
  • Separate waste area
  • No hidden rounding

Step 3 · Trade units

Convert roof area to roofing squares

Save to this browser
One roofing square = 100 square feet. The waste allowance is added after the measured roof area and is shown separately.

Order quantity

Squares with waste

19.8

1,980 sq ft total order area

Base squares

18

Measured area ÷ 100

Waste area

180 sq ft

10% of measured area

Measured area

1,800 sq ft

Before waste

Squares can be fractional. Packaged materials must still be rounded up by their actual coverage, which the next calculators handle.

Build a complete material order

Transparent

Formula, intermediate values and rounding rules are visible.

Private by default

Saved project measurements stay in this browser unless you copy a share link.

Purchase-aware

Inputs, units and limitations stay visible so you can verify each estimate.

What is a roofing square?

A roofing square is a trade unit equal to 100 square feet of installed roof coverage. It makes roofs and material quantities easier to compare without repeatedly writing large square-foot values.

The calculator reports the measured roof in squares, then applies the selected waste allowance once. It does not round the result to bundles because package coverage varies; use the Shingle Calculator for that purchase step.

Base squares

measured roof area ÷ 100

Roof size before a material allowance.

Waste area

measured area × waste %

Cuts and unusable material shown separately.

Order squares

(measured area + waste area) ÷ 100

Area basis for the material order.

How to use this calculator

  1. 1Enter sloped roof surface area, not the building footprint.
  2. 2Choose a waste allowance based on roof layout and product guidance.
  3. 3Use the exact order-square result for comparison and quoting.
  4. 4Round only when converting to actual bundles, rolls or pieces.

Common mistakes

  • • Dividing the flat footprint by 100 before adjusting for pitch.
  • • Confusing a 10% allowance with adding 10 roofing squares.
  • • Rounding down fractional squares.
  • • Adding waste here and again in a bundle calculation.

Use this calculator when

  • You already have measured sloped roof area in square feet.
  • You need base squares and order squares shown separately.

Use another method when

  • Your only measurement is the building footprint.
  • You need the actual number of bundles for a specific product.

Worked example

1,800 sq ft roof with 10% waste

The measured roof is 18 squares. Ten percent adds 180 sq ft, or 1.8 squares.

1,980 sq ft ÷ 100 = 19.8 order squares

Frequently asked questions