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Roofing Calculators

Roofing Material Calculator

Tiles, slates or sheets needed for a roof, with battens, underlay and ridge tiles.

Enter values

Results update as you type.

Result

Units required

1,223

Units per m²
9.7
Battens
347.8 linear m
Underlay (1 m × 50 m rolls)
3
Ridge tiles (300 mm)
40
Nails (approx)
1,835
Material cost
$1,467.60

About the Roofing Material Calculator

Tiles, slates or sheets needed for a roof, with battens, underlay and ridge tiles.

Also known as: roof tiles calculator, how many roof tiles, slate calculator, roofing quantity.

How to use this calculator

  1. Enter roof area, material, waste allowance, ridge length and the other fields.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

units = roof area × (1 + waste) × units per m²

Worked example

Using the values pre-filled in the calculator above:

  • Roof area = 120 m²
  • Material: Interlocking concrete tile (9.7/m²)
  • Waste allowance = 5 %
  • Ridge length = 12 m
  • Price per unit = 1.2

the calculator returns:

  • Units required: 1,223
  • Units per m²: 9.7
  • Battens: 347.8 linear m
  • Underlay (1 m × 50 m rolls): 3