Roofing Shingles
Free Roofing Shingles calculator with clear step-by-step results.
About Roofing Shingles
Shingle orders have four separate components. The field is area over bundle coverage with waste, ridge and hip caps come out of dedicated bundles covering roughly eight metres each, starter strip runs along the eaves, and valleys need flashing with a length allowance for laps.
Formulas
Field bundles
Bundles = ceil(sloped area x (1 + waste) / coverage per bundle)
Cap bundles
Bundles = ceil(ridge and hip length / 8 metres per bundle)
Worked example
With the default values below, Roofing Shingles returns Total bundles to order of 55. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Sloped roof areaminimum 0.5 m2
- 140 m2
- Coverage per bundleminimum 0.1 m2
- 3.1 m2
- Ridge and hip lengthminimum 0 m
- 18 m
- Eaves length for starter stripminimum 0 m
- 24 m
- Valley lengthminimum 0 m
- 6 m
- Waste allowanceaccepts 0–40 %
- 12 %
Results
- Total bundles to order
- 55 bundles
- Bundles for the main field
- 51 bundles
- Bundles for ridge and hip caps
- 3 bundles
- Valley flashing
- 7 m
Step by step
- 1Values used
- 2Field bundles
- 3Cap bundles
- 4Total bundles to order= 55 bundles
- 5Bundles for the main field= 51 bundles
- 6Bundles for ridge and hip caps= 3 bundles
- 7Valley flashing= 7 m
Assumptions and limits
- The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
Why is waste 12% rather than 5%?
Hips, valleys, rake edges and cap cutting all generate offcuts. A simple gable roof can manage 8%; a cut-up roof with dormers can exceed 15%.
Can I use field shingles as ridge caps?
Three-tab shingles can be cut into caps, but architectural laminated shingles cannot - they are too thick to fold over the ridge and need purpose-made caps.