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Gravel Calculator

Work out how much gravel you need for a driveway, path or base, in tons and cubic yards, with the number of bags and the cost. Measurements can go in as feet and inches, or as metres and centimetres.

Dimensions

Area entry

An estimate: about 1.66 tonnes per m³. It varies with stone type and moisture.

The volume of one bag, for example 0.5 ft³ or 20 L.

Estimated gravel needed

1.30tons

Waste: none added

Cubic yards
0.93 yd³
Cubic feet
25.00 ft³
Cubic metres
0.71 m³
Estimated tonnes
1.18 tonnes

Formula

25 ft × 4 ft × 3 in

= 25 ft × 4 ft × 0.25 ft = 25.00 ft³

25.00 ft³ ÷ 27 = 0.93 yd³

Estimated weight: 0.93 yd³ × 1.4 tons per yd³ = 1.30 tons

Quick answer

To find how much gravel you need, multiply the area by the depth in feet and divide by 27 for cubic yards, then multiply by about 1.4 to get tons, since a cubic yard of gravel weighs roughly 1.4 tons. A 100 square foot path at 3 in deep is 25 cubic feet, which is 0.93 cubic yards, or about 1.3 tons.

How to use the gravel calculator

  1. Measure the ground to cover, then enter its length and width, or type the total area.
  2. Enter the depth, or use a typical depth for a driveway, path or base.
  3. Add a price per ton or per cubic yard, and a bag size if you are buying bags.
  4. The result lists tons, cubic yards, cubic metres, bags and cost.
  5. Work in feet and inches or in metres, and the tons and yards update together.

Worked example

A path is 25 ft long and 4 ft wide, for 100 square feet, at 3 in deep.

  1. 1.Depth in feet: 3 / 12 = 0.25 ft
  2. 2.Cubic feet: 100 x 0.25 = 25
  3. 3.Cubic yards: 25 / 27 = 0.93
  4. 4.Tons: 0.93 x 1.4 = about 1.3 tons

When to use this

  • A driveway: work out the coarse base and the finer top layer separately, in tons.
  • A garden path: decide between bulk delivery and bags for a small amount of pea gravel.
  • Drainage: estimate the gravel for a trench or soakaway.

The formula

Two steps take you from area to tons:

cubic yards = area (sq ft) x depth (ft) / 27, then tons = cubic yards x 1.4.

A cubic yard is 27 cubic feet. Gravel weighs about 1.4 tons per cubic yard, though this varies with the stone and how wet it is. Inches of depth become feet by dividing by 12, and the answer also appears in cubic metres and tonnes.

Gravel per 100 square feet by depth

Scale up by your area in hundreds of square feet. Tons use 1.4 tons per cubic yard.

Depth Cubic yards Tons
2 in 0.62 0.86
3 in 0.93 1.30
4 in 1.23 1.73
6 in 1.85 2.59

Swipe sideways to see all columns

Choosing a stone and layering a driveway

Gravel comes in several forms, and the choice affects both the look and how it holds together. Crushed stone with sharp edges locks tightly and makes a firm base, while rounded pea gravel is softer underfoot but shifts more, so it suits paths and borders rather than a driveway surface. Angular stone in the 3/4 in range is a common all-round choice. A driveway is built in layers: a coarse sub-base of larger stone 4 to 6 in deep for strength, then a finer top layer 2 to 3 in deep for the surface. Work out each layer separately and add them, since they use different stone and different depths. On soft or wet ground, add a landscape fabric under the base to stop the stone sinking, and allow extra depth. Compact each layer before adding the next so the finished level is right.

Common mistakes

  • Buying by volume when the supplier sells by weight. Gravel is often priced by the ton, so compare quotes on the weight figure.
  • Too shallow a base. A driveway needs a deeper base than a path, so pick the right depth.
  • Forgetting to convert the depth. A depth in inches has to become feet before you multiply, and the calculator does this for you.
  • Forgetting it settles. Gravel compacts, so order a little extra.
  • Using one weight for every stone. Rounded pea gravel and crushed stone differ, so treat the tonnage as an estimate.

Frequently asked questions

Work out the area and the depth, then read the tons and cubic yards. A 100 square foot path at 3 in deep needs about 0.93 cubic yards, or roughly 1.3 tons.

References. The formulas and figures here follow standard construction references. See our Methodology for how we check them. Gravel volume uses standard geometry (a cubic yard is 27 cubic feet).

Estimates only. Check supplier specs and local codes before you order or build.