Work out how many roof shingles and bundles you need from your roof footprint and pitch, with a wastage allowance for cuts, ridges and starter courses.
| Item | Value |
|---|
Asphalt and composite shingles are measured in "squares" — one square covers 100 square feet (about 9.29 m²) of roof. Shingles are sold in bundles, and it usually takes three bundles to cover one square, though heavier architectural shingles may need four.
| Shingle type | Bundles per square | Notes |
|---|---|---|
| Standard 3-tab asphalt | 3 | Most common, lightest |
| Architectural / laminate | 3–4 | Heavier, longer lasting |
| Premium / designer | 4–5 | Thickest profile |
| Tip | Why it matters |
|---|---|
| Measure the plan footprint, not the slope | The calculator applies the pitch factor for you |
| Add 10–15% wastage | Covers cuts at hips, valleys, ridges and starter rows |
| Buy from one batch | Colour can vary slightly between production runs |
| Keep a few spare bundles | Storm repairs are easier with matching shingles on hand |
How many bundles of shingles do I need?
It usually takes three bundles of standard asphalt shingles to cover one roofing "square" (about 9.29 m²). Work out your roof area, divide by 9.29 to get squares, then multiply by three. This shingle calculator does all of that and adds a wastage allowance — just enter your roof footprint and pitch.
How do I measure my roof area for shingles?
Measure the length and width of the building footprint, then account for the roof slope using the pitch. A steeper roof has more actual surface area than its footprint suggests, so the calculator multiplies by a pitch factor to give the true area to shingle.
How much extra should I order for wastage?
Allow 10–15% extra for cuts around hips, valleys, ridges, and starter courses — more on a complex roof with many angles. The calculator defaults to 12%. It is also worth keeping a few spare shingles from the same batch for future storm repairs.