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How much tarmac do I need?

Area and laid depth in — tonnage out, so you can order the right load rather than guessing at the weighbridge.

m

Length of the area to pave.

m

Width of the area.

cm

Around 5–8 cm (2–3 in) is typical for a driveway.

£

Optional — enter what you pay and the material cost appears below.

You'll need about

10.0

t of asphalt

4.32

72

Quoting a paving job? Turn the tonnage into a priced estimate. Build a free estimate.

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How this is calculated

area × depth = volume · volume × 2,323 kg/m³ ≈ weight. Tarmac is bought by the tonne but specified by depth, so the conversion is where the ordering error usually creeps in.

This is a planning estimate — always confirm against your supplier and the specifics of the job before ordering.

Tarmac calculator: FAQ

How much tarmac do I need for a driveway?

Multiply the area by the laid depth, then convert to tonnes. A 40 m² drive at 50 mm compacted needs 2 m³, which is roughly 4.6 tonnes. Order in whole loads where you can — a part load usually carries a surcharge that dwarfs the material saved.

What depth should tarmac be laid at?

A domestic drive is commonly finished with a 20–25 mm wearing course over a 40–50 mm base, on a compacted sub-base. Anything taking regular vehicle weight or turning needs more, and the sub-base matters more than the tarmac depth — most failed drives failed underneath.

Is tarmac the same as asphalt?

In everyday use, yes. Strictly, tarmac is the older tar-bound material and what is laid now is bitumen-bound asphalt, but the trade and the customer both say tarmac and mean the same driveway.

How much does a tonne of tarmac cover?

At 50 mm depth, about 9 m² per tonne. That figure halves if you double the depth, which is why quoting off area alone without agreeing a depth is how a job loses money.

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