How this calculator works
Length times width times layer depth gives net volume. Multiply by bulk density to estimate delivered mass and apply any extra ordering allowance. The example density is for clean stone; obtain the driveway grading and density from your supplier.
Formula
A = L x W, pi x D^2 / 4, b x h / 2, or (front + back) x h / 2; Vnet = A x depth; Vorder = Vnet x (1 + waste); mass = Vorder x density; cost = tonnes x rate or Vorder x rate, plus fixed charges.
Worked example
A 20 m by 3 m drive with a 0.1 m layer needs 6 m3. At 1800 kg/m3 without waste, that is 10.8 tonnes.
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Frequently asked questions
Can I combine different driveway layers?
Calculate each layer with its own thickness and density, then add the costs. A single average density may hide a large error.
Does the tool choose a suitable base?
No. Drainage, frost, subgrade and traffic determine the section. Enter the layer specified for your site.
What does the reverse depth mode mean?
It divides a known net mass by density and covered area. Ordering waste is separate from that net mass.