Driveway Calculator
Calculate materials for a driveway including sub-base and surface layers.
Please note: Material estimates for planning only. Always confirm quantities against your drawings, local building codes and supplier specifications before ordering. Structural work requires a qualified engineer.
What the Driveway Calculator does
A driveway is built in layers: a compacted stone sub-base carrying the load, and a surface layer on top. Each is calculated as area times depth times material density, and the excavation must accommodate both.
Formula
Area = Length × WidthLayer volume = Area × Layer depth × (1 + Waste %)Tonnes = Volume × Density ÷ 1,000Excavation depth = Sub-base + Surface
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Driveway length | number | Yes | Accepts more than 0. |
| Driveway length unit | one of 6 options | Yes | — |
| Driveway width | number | Yes | Accepts more than 0. |
| Driveway width unit | one of 6 options | Yes | — |
| Sub-base depth | number | Yes | Accepts more than 0. |
| Sub-base depth unit | one of 5 options | Yes | — |
| Surface layer depth | number | Yes | Accepts more than 0. |
| Surface layer depth unit | one of 5 options | Yes | — |
| Surface material | one of 3 options | Yes | — |
| Waste allowance | % | Yes | — |
| Sub-base price per tonne | selected currency | Optional | Accepts 0 or more. |
| Surface price per tonne | selected currency | Optional | Accepts 0 or more. |
| Currency | one of 10 options | Optional | — |
How to use it
- Choose Driveway length unit and Driveway width unit.
- Enter Driveway length, Driveway width, Sub-base depth and Surface layer depth and 1 more.
- Optionally add Sub-base price per tonne and Surface price per tonne.
- Select Calculate.
Worked example
A 12 m × 3 m driveway, 150 mm sub-base, 50 mm gravel surface, 10% waste.
- Length
- 12 m
- Width
- 3 m
- Sub-base
- 150 mm
- Surface
- 50 mm
- Material
- Gravel
Area 36 m². Sub-base 5.94 m³ = 11.88 tonnes, gravel 1.98 m³ = 3.33 tonnes. Excavate 200 mm = 7.2 m³.
Frequently asked questions
How deep should a driveway sub-base be?
100–150 mm of compacted MOT type 1 for cars. Go to 200–250 mm for vans or regular heavy vehicles.