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Concrete, Masonry & Stone

Gravel Calculator

Work out how much gravel a project needs, in the units your supplier sells it by. Enter the area and the finished depth, pick the material, and add a waste allowance for settling and spillage.

Your measurements

Each field has its own units, so you can mix feet and inches.

Area to cover
2–3 in suits a walkway. Driveways usually need 4 in or more.
Material
Pick the closest product, or choose custom to enter a density from your supplier's sheet.
Typical loose crushed stone is 95–110 lb/ft³. Damp stock weighs more.
Added to the final quantity. Ten percent covers most jobs.

Your result

Sample values

16.67

Cubic yards

450.0

Cubic feet

8.20

Tons

16,400

Pounds

Includes a 10% waste allowance.

What to order

Sold as Quantity
Bulk, by the ton8.20 tons
Bulk, by the yard16.67 yd³
50 lb bags328 bags
1 ton bulk bags9 bags

How to use this calculator

  1. Measure the length and width of the area you are covering.
  2. Decide the finished depth — the depth you want once the gravel is raked level and compacted, not the loose depth as it comes off the truck.
  3. Pick the product. If your supplier quotes a density, choose custom and enter their figure instead of the default.
  4. Leave the waste allowance at 10% unless the area is awkward or the material is sold in fixed pallet quantities.

Measuring an irregular area

Split the shape into rectangles, run each one separately and add the results. For a curved bed, take the average width across several points and treat it as a rectangle — it is close enough at gravel depths.

Formula

Volume (ft³) = Length × Width × Depth

Cubic yards = Volume ÷ 27

Weight (lb) = Volume × Density

Tons = Weight ÷ 2000

Depth
Converted to feet first — 4 in becomes 0.333 ft
Density
Loose weight per cubic foot, from your supplier

The waste allowance is applied to the final quantity, after the conversion to yards or tons.

A 24 × 30 ft driveway

Laying 4 in of 3/4 in crushed stone at 105 lb/ft³, with a 10% waste allowance.

  1. Area = 24 × 30 = 720 sq ft
  2. Depth in feet = 4 ÷ 12 = 0.333 ft
  3. Volume = 720 × 0.333 = 240 ft³
  4. Plus 10% waste = 264 ft³
  5. Cubic yards = 264 ÷ 27 = 9.78 yd³
  6. Weight = 264 × 105 = 27,720 lb

Order 13.9 tons, or 14 one-ton bulk bags.

Understanding your results

The calculator gives the same quantity four ways because suppliers do not agree on how to sell aggregate. Bulk yards are common for landscape supply, tons for quarries, and bagged product for small jobs where a delivery is not worth arranging.

Why the tonnage is the softest number

Cubic feet and cubic yards follow directly from your measurements, so they are as accurate as your tape. Weight depends on density, which changes with the product, the stone size, how tightly it is packed and how wet it is. The same yard of crushed stone can vary by several hundred pounds between a dry summer load and a wet winter one.

Getting the depth right

Depth drives the total more than people expect. On a 720 sq ft driveway, one extra inch is roughly another 2.2 cubic yards — about three tons, and often the difference between one delivery and two. Measure the depth you want finished, then let the waste allowance absorb the settling.

Questions

About this calculator

Ask something else

For a footpath, 2 to 3 inches over a compacted base is enough. A parking area or driveway carrying cars wants 4 inches of top course over 4 or more inches of larger base stone. Anything taking delivery lorries or plant needs a deeper base again, specified for the load.

Measure the finished depth you want once the gravel is compacted. Loose stone settles by roughly a fifth as it beds in, and the waste allowance covers that.

The 105 lb/ft³ default is a reasonable middle figure for dry crushed stone. Pea gravel and river rock run a little lighter, at about 95 to 100. Damp material can be 5 to 10 percent heavier, so if you are ordering by weight in wet conditions you will get slightly less volume than the number suggests.

For a bed or border, no — a weed membrane over firm soil is enough. For anything driven on, yes: a compacted sub-base of larger angular stone stops the top course working down into the ground. Calculate the two layers separately, since they use different products.

Because you cannot buy part of one. Bag and bulk bag counts are always rounded up to the next whole unit, which is why the bag figure can look slightly generous against the tonnage.

Keep going

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Estimates, not specifications. Results are based on the values you enter and on typical material properties. Densities, coverage rates and product sizes vary between suppliers, so confirm quantities against your supplier's data before ordering. Structural work must be signed off by a qualified professional and meet your local building code.