🪨 Gravel Calculator

Enter length, width, and depth to calculate how much gravel you need by volume and weight.

Length (m)

Width (m)

Depth (cm)

Material type

Price per metric ton (optional)

Volume needed

— m³

Weight needed

— t

GUIDE

Learn more

How the area × depth to volume-and-tons calculation works

Gravel needed is found by multiplying area (㎡) × depth (m) = volume (㎥), then multiplying that by the material's density (t/㎥) to get weight in tons. For example, a 5m × 2m area is 10 ㎡; spread at a 10cm (0.1m) depth that's 10 × 0.1 = 1.0 ㎥ of gravel, and at the default gravel density of 1.68 t/㎥ that comes to 1.0 × 1.68 = 1.68 tons. In imperial units, volume converts to cubic yards (1 yd³ = 0.764555 ㎥) and weight converts to US short tons (907.18474 kg).

Choosing the right depth for common projects

Depth depends on what you're building. A driveway base layer is typically around 10cm (4in) to support compaction and vehicle loads, a walkway topping layer usually only needs about 5cm (2in), and a drainage bed should generally be 15cm (6in) or more to move water effectively. Garden mulch beds often work fine at 5-7cm, while heavier-use areas like parking pads are safer closer to 10-15cm.

Avoiding over- or under-ordering gravel

Because compaction and handling losses reduce your effective coverage, it's wise to order roughly 10% extra beyond the calculated amount. Densities also vary by supplier and gravel type, so if your supplier lists their own bulk density, use that figure instead of this calculator's default for a more accurate estimate. If a supplier quotes pricing per cubic yard/meter or per ton rather than a flat rate, you can plug this tool's volume or weight output directly into their unit price to get your total cost.

Frequently asked questions

Why does density vary by gravel type, and why does it matter?

Particle size, shape, and how tightly the material packs all affect how much a given volume weighs. Because density differs across gravel types, the same volume can require a different number of tons — picking the material closest to what you're actually buying keeps the weight and cost estimate accurate.

How do I measure an irregularly shaped area?

Break the space into a few rectangles (or triangles), calculate the area of each piece separately, then add them together. For an L-shaped area, for instance, split it into two rectangles, run each through the calculator, and sum the results.

Should I add extra margin beyond the calculated amount?

Yes. Compaction, spillage during handling, and uneven ground typically eat into your coverage, so ordering about 10% extra beyond the calculated volume or weight is a common safety margin.

My supplier prices gravel per ton or per cubic yard — how does that relate to this tool's output?

This calculator shows both the volume (㎥ or yd³) and weight (tons) you need, so you can multiply whichever figure matches your supplier's pricing unit. If they quote per ton, use the weight result; if per cubic yard/meter, use the volume result. Entering a price per ton in the tool will also calculate the estimated total cost automatically.