Gravel Calculator

How much gravel you need for a driveway, path or border: cubic yards or m³, tons or tonnes, and bags, for rectangles, circles and triangles.

Gravel is sold by volume (cubic yards or cubic metres) or by weight (tons or tonnes), so you need both. Volume is area × depth: a 12 × 10 ft area 3 inches deep is 30 cubic feet, or 1.11 cubic yards. Loose gravel weighs about 1.35 US tons per cubic yard (1.6 tonnes per m³), so that's about 1.5 tons. This calculator works out the volume and weight for any mix of rectangles, circles and triangles, adds an allowance for waste, and counts bags in US, UK and Australian sizes, from 0.5 ft³ bags to 850 kg and 1 tonne bulk bags. Density varies with the stone, so you can change it to your supplier's figure, and switch between gravel, pea gravel, river rock, crushed stone and more.

Units

Bag sizes

Material

Area

Shape

Length

Width

Depth

Feet and inches work too: type 12'6 or 12.5.

Density (tons per cubic yard)

t/yd³

Extra for waste and compaction

Bag size

Volume: 1.17 yd³
Weight: 1.58 tons
Bags: 63

Bags needed by size
0.5 ft³ bag	63
25 kg bag	58
20 kg bag	72
850 kg bulk bag	2
1 tonne bulk bag	2

Price (optional)

Price is per

How it was worked out

Area: 12 ft × 10 ft = 120 ft²; × 3 in (0.25 ft) deep = 30 ft³
30 ft³ ÷ 27 = 1.11 yd³
Plus 5% extra = 1.17 yd³
1.17 yd³ × 1.35 tons per yd³ = 1.58 tons (3,150 lb)
31.5 ft³ ÷ 0.5 ft³ per bag = 63, rounded up to 63 bags

Typical weights of common materials

Material	t/m³	tons/yd³	lb/ft³
Concrete	2.40	2.02	150
Gravel	1.60	1.35	100
Pea gravel	1.60	1.35	100
Crushed stone / crushed rock	1.60	1.35	100
River rock	1.50	1.26	94
Landscape rock / pebbles	1.50	1.26	94
Crushed limestone	1.60	1.35	100
Decomposed granite	1.50	1.26	94
Crusher run	1.60	1.35	100
Road base	1.70	1.43	106
Crusher dust	1.50	1.26	94
Aggregate (20 mm)	1.60	1.35	100
All-in ballast	1.65	1.39	103
MOT Type 1 sub-base	1.80	1.52	112
Sand	1.60	1.35	100
Topsoil	1.30	1.10	81
Garden soil	1.30	1.10	81
Fill dirt	1.40	1.18	87
Mulch	0.35	0.29	22
Bark chippings	0.30	0.25	19
Asphalt (compacted)	2.32	1.96	145

Loose, as-delivered figures; asphalt and concrete are as laid. Moisture, stone size and source change the real weight, so use your supplier's figure when you have it. Tons are US short tons (2,000 lb).

Common use cases

Gravel for a driveway, parking area or path
Decorative gravel for borders and around plants
Drainage gravel for French drains, soakaways and behind retaining walls
Comparing bags with a bulk delivery

How to use

Choose feet and inches or metres and millimetres, and the country whose bag sizes you want.
Enter the length and width of the area, or switch the shape to a circle, triangle or a known area. Use Add another area for L-shapes and separate beds.
Enter the depth of gravel. Paths often take 2 to 3 inches (50 to 75 mm), driveways 4 inches (100 mm) or more over a compacted base.
Check the density and the extra allowance. Change the density if your supplier quotes a different figure.
Read the volume, weight and bag count, and add a price per ton, cubic yard, m³ or bag for a cost estimate.

FAQ

How much does a cubic yard of gravel cover?

A cubic yard covers about 324 ft² at 1 inch deep, 162 ft² at 2 inches, 108 ft² at 3 inches and 81 ft² at 4 inches. In metric, a cubic metre covers 20 m² at 50 mm or 13.3 m² at 75 mm.

How much does gravel weigh?

Loose gravel is typically around 1.35 to 1.5 US tons per cubic yard (1.6 to 1.8 tonnes per m³), depending on the stone, the sizes and how wet it is. The calculator starts at 1.6 t/m³; enter your supplier's figure if they give one.

How deep should gravel be?

Decorative gravel over a weed membrane is usually 1.5 to 2 inches (40 to 50 mm) deep. Paths are often 2 to 3 inches. A driveway usually has a compacted base of larger crushed stone with 2 to 3 inches of finer gravel on top. Too deep and loose gravel is hard to walk and drive on.

How much does a tonne of gravel cover?

At 1.6 tonnes per m³, a tonne is about 0.63 m³, which covers about 12.5 m² at 50 mm deep or 8.3 m² at 75 mm. An 850 kg bulk bag covers about 10.6 m² at 50 mm.