Shingle Calculator
Works out shingle bundles from the roof area, plus the starter course, ridge caps and nails that are easy to forget on the order.
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The formula
squares = area × (1 + waste) ÷ 9.29 m² bundles = squares × bundles per square
A roofing square is 100 square feet, a unit that exists purely because shingles have always been sold that way. Three bundles to a square is the standard for ordinary shingles — heavyweight and designer profiles take four or five, and the pack states it.
What to watch out for
Three separate products go on a shingle roof and only one of them is field shingles:
- Field shingles — the main area, three bundles to the square.
- Starter course — along every eave, and up the rakes on many systems. A bundle covers roughly 30 m.
- Ridge and hip caps — a bundle covers around 10 m.
Four nails per shingle is standard, six in high-wind zones, and the manufacturer's warranty usually depends on it. Nail placement matters as much as count — too high and the nail misses the shingle beneath, which is the most common cause of blow-offs.
Frequently Asked Questions
How many bundles of shingles do I need?
Three bundles per roofing square for standard shingles. A 100 m² roof plus 10% waste is 11.8 squares, so 36 bundles of field shingles before starter and ridge.
How many shingles in a square?
A square covers 100 square feet, which is three bundles of standard shingles — usually 29 shingles per bundle for three-tab, so about 87 shingles.
How many nails per square of shingles?
About 320 at four nails per shingle, which is roughly 1.4 kg. High-wind areas call for six nails per shingle, putting it near 480.