How many tonnes of gravel are in a cubic metre?

About 1.5 tonnes for loose gravel or crushed stone; sand is nearer 1.6 and topsoil about 1.2. Suppliers quote their own density for each product, and the calculator lets you type it in.

How deep should driveway gravel be?

As a top layer over a compacted sub-base, 50 to 75 mm (2 to 3 in) is typical: enough to hide the base, thin enough that tyres do not sink. The sub-base under it is separate and usually 100 to 150 mm of compacted crushed stone (MOT type 1, crusher run or similar).

How many bulk bags for a 3 x 6 m driveway?

3 bulk bags at 75 mm deep, assuming a bag holds about 850 kg. Bag weights vary by supplier and material, so check before ordering; loose delivery by tipper is usually cheaper per tonne once you need several bags.

Can I lay gravel straight onto soil?

Not for a driveway. The stone sinks into the ground and spreads under the wheels. Dig out, lay a geotextile membrane, compact a stone sub-base, contain the edges, then add the gravel layer.

How much gravel do I need for a driveway?

A single-car driveway of 3 x 6 m topped with 75 mm of gravel needs about 1.42 m³, which at a typical bulk density of 1.5 t/m³ is 2.1 tonnes or 3 bulk bags. That already includes 5% extra for levelling and compaction. Other sizes, depths and the imperial version are in the tables.

Open the gravel calculator

Gravel for typical driveways

Volume is area x depth. Weight is volume x density, and the tables use 1.5 t/m³, the usual figure for loose gravel and crushed stone. Bulk bags are assumed to hold about 850 kg. Everything includes 5% extra for uneven ground and compaction.

Gravel top layer, 1.5 t/m³, 5% extra included
Driveway	Area (m²)	Depth	Volume (m³)	Tonnes	Bulk bags (850 kg)
Single car, 3 x 6 m	18	50 mm	0.95	1.42	2
Single car, 3 x 6 m	18	75 mm	1.42	2.13	3
Single car, 3 x 6 m	18	100 mm	1.89	2.84	4
Double, 6 x 6 m	36	50 mm	1.89	2.84	4
Double, 6 x 6 m	36	75 mm	2.84	4.25	6
Double, 6 x 6 m	36	100 mm	3.78	5.67	7
Long single, 3.5 x 15 m	52.5	50 mm	2.76	4.13	5
Long single, 3.5 x 15 m	52.5	75 mm	4.13	6.2	8
Long single, 3.5 x 15 m	52.5	100 mm	5.51	8.27	10

Two layers, two calculations

A gravel driveway is built in layers, and each one is its own material and its own order:

Sub-base: 100 to 150 mm of crushed stone with fines (MOT type 1, crusher run, road base) compacted in passes with a plate compactor. This carries the load.
Top layer: 50 to 75 mm of the decorative gravel you actually see (10 to 20 mm pea gravel, golden gravel, slate chippings and so on).

Run the gravel calculator once for each layer with its own depth and density. A membrane between the soil and the sub-base stops the stone disappearing into the ground over time.

Imperial: cubic yards and tons

Same driveways in feet and inches. US suppliers sell by the cubic yard or by the ton (2,000 lb); one cubic yard of gravel weighs roughly 1.26 tons at the density above.

Gravel top layer, 5% extra included
Driveway	Area (sq ft)	Depth	Volume (cu yd)	US tons
Single car, 10 x 20 ft	200	2 in	1.3	1.64
Single car, 10 x 20 ft	200	3 in	1.94	2.46
Single car, 10 x 20 ft	200	4 in	2.59	3.28
Double, 20 x 20 ft	400	2 in	2.59	3.28
Double, 20 x 20 ft	400	3 in	3.89	4.92
Double, 20 x 20 ft	400	4 in	5.19	6.55
Long single, 12 x 50 ft	600	2 in	3.89	4.92
Long single, 12 x 50 ft	600	3 in	5.83	7.37
Long single, 12 x 50 ft	600	4 in	7.78	9.83

Bulk bags or loose delivery?

Bulk bags are convenient for small jobs and can be craned onto a drive or pavement. Weights vary by material and supplier, and a bag of wet gravel is heavier than the same volume dry.
Loose (tipper) delivery is normally cheaper per tonne above a few tonnes but needs somewhere to tip the pile and a way to move it.
Order the top layer after the sub-base is compacted and you have measured the depth that is actually left to fill: it is often less than the plan said.

Frequently asked questions

How many tonnes of gravel are in a cubic metre?: About 1.5 tonnes for loose gravel or crushed stone; sand is nearer 1.6 and topsoil about 1.2. Suppliers quote their own density for each product, and the calculator lets you type it in.
How deep should driveway gravel be?: As a top layer over a compacted sub-base, 50 to 75 mm (2 to 3 in) is typical: enough to hide the base, thin enough that tyres do not sink. The sub-base under it is separate and usually 100 to 150 mm of compacted crushed stone (MOT type 1, crusher run or similar).
How many bulk bags for a 3 x 6 m driveway?: 3 bulk bags at 75 mm deep, assuming a bag holds about 850 kg. Bag weights vary by supplier and material, so check before ordering; loose delivery by tipper is usually cheaper per tonne once you need several bags.
Can I lay gravel straight onto soil?: Not for a driveway. The stone sinks into the ground and spreads under the wheels. Dig out, lay a geotextile membrane, compact a stone sub-base, contain the edges, then add the gravel layer.

Last updated 2026-09-11. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.