S
SenseCalc
Updated 1 May 2026

Tarmac Calculator · Free UK Cost & Tonnes 2026

Calculate how many tonnes of tarmac you need for your driveway or path, plus a cost estimate based on 2026 UK installation rates.

✓ Free to use✓ Tonnes & area✓ 2026 UK prices✓ Instant results

Tarmac Calculator

Enter dimensions, tonnes needed and cost estimate appear instantly

m
m
mm

Tarmac needed

1.80 tonnes

Area: 15.0 m², installed cost estimate: £675.00–£1,200.00

Length × Width

5m × 3m

Area

15.00 m²

Depth

50 mm

Volume

0.750 m³

Tarmac density

2.4 t/m³

Tarmac needed

1.80 tonnes

Installation cost (est.)

£675.00 – £1,200.00

Uses 2.4 t/m³ for compacted tarmac. Cost estimates (£45–£80/m²) cover the wearing course and typical installation, sub-base, edging, and VAT may be additional. Always obtain 3 quotes.

How to Calculate Tarmac Quantities

Quick Answer: Tarmac (tonnes) = Length × Width × Depth (metres) × 2.4. A 5m × 3m driveway at 50mm depth needs 1.8 tonnes for the wearing course. Fully installed cost is £45–£80 per m² (2026).

Formula

Tonnes = Length (m) × Width (m) × Depth (m) × 2.4 t/m³

e.g. 5 × 3 × 0.05 × 2.4 = 1.8 tonnes

Worked Example: 5m × 3m driveway, 50mm wearing course

Length5 m
Width3 m
Depth50 mm (0.05 m)
Area15 m²
Volume0.75 m³
Tarmac needed (× 2.4 t/m³)1.8 tonnes
Installation cost (£45–£80/m²)£675–£1,200

Covers wearing course only. Sub-base (MOT Type 1), binder course, and edging are additional costs.

Frequently Asked Questions

To calculate tarmac quantity, multiply length × width × depth (in metres) × density (2.4 t/m³). For a standard driveway the recommended wearing course depth is 40–60mm. A 5m × 3m driveway at 50mm depth needs 5 × 3 × 0.05 × 2.4 = 1.8 tonnes for the top layer alone, the sub-base and binder course are additional.