GRAVEL CALCULATOR

Gravel Calculator — How Much Gravel Do I Need?

Estimate the volume and weight of gravel, pea gravel, crushed stone or decomposed granite for driveways, paths, drainage layers and landscaping projects. Enter the area dimensions, depth and material type to get a quick estimate with waste allowance.

Gravel type

Area dimensions

Depth

Typical driveway: 8–10 cm. Pathway: 5–7 cm.

Waste allowance

Total gravel needed
—m³

Fill in dimensions to see your estimate.

Estimate Gravel by Volume and Weight for Any Landscaping or Construction Project

The Interior Tailor Gravel Calculator estimates how much gravel, crushed stone, pea gravel or decomposed granite you need for driveways, paths, drainage layers and landscaping projects. Choose your material, enter the length, width and depth of the area, and add a waste allowance. You get the total volume to order and an estimated weight based on the typical bulk density of the material you selected, which helps whether your supplier sells by the cubic yard, the cubic metre or by weight.

What the Gravel Calculator Includes

  • Five materials: pea gravel, crushed stone, decomposed granite, river rock and coarse sand.
  • Metric or imperial: metres and centimetres, or feet and inches.
  • Depth guidance built in: typical depth hints for driveways and pathways right beside the depth field.
  • Waste allowance: a percentage for compaction, uneven ground and spreading losses.
  • Volume and weight: an estimate of the quantity to order and its approximate weight.

How Gravel Volume Is Calculated

The basic formula multiplies area by depth:

Volume = Length × Width × Depth

Weight is then estimated using the typical bulk density of the selected material. A waste allowance of 10% is added to account for compaction, uneven ground and spreading losses. Always round up to the nearest whole unit when ordering.

Gravel Depths by Application

  • Driveways (base layer): 10–15 cm (4–6 in) compacted depth
  • Driveways (surface layer): 5–8 cm (2–3 in) of pea gravel or crushed stone
  • Pathways: 5–8 cm (2–3 in)
  • French drains / drainage: 10–15 cm (4–6 in)
  • Decorative landscaping: 5–7 cm (2–3 in)
  • Concrete sub-base: 10 cm (4 in) minimum compacted

Gravel Material Types Compared

  • Pea gravel: Rounded, smooth, 3/8–1/2 in. Comfortable underfoot, tends to scatter. Good for paths and play areas.
  • Crushed stone (#57): Angular, compacts well. Best for driveways, drainage and sub-base.
  • Decomposed granite: Fine-grained, packs into a firm surface. Popular for desert landscaping and paths.
  • River rock: Rounded, decorative. Used in dry stream beds and ornamental landscaping.
  • Coarse sand: Fine particles, packs tightly. Used as paver setting bed.

Gravel Projects You Can Plan

Use the calculator for any flat area filled to a consistent depth:

  • Driveway base and surface layers
  • Garden paths and walkways
  • French drains and drainage layers
  • Concrete sub-base under slabs and patios
  • Decorative beds, dry stream beds and play areas
  • Paver setting beds with coarse sand

Example Gravel Estimates

Each example adds a 10% waste allowance. Weights use the densities listed on this page and are rounded.

Example Gravel Estimates
ProjectMaterialInputsVolumeWith 10% wasteApprox. weight
Garden pathPea gravel20 ft x 3 ft x 2 in0.37 cu yd0.41 cu ydabout 1,020 lb
Driveway sectionCrushed stone10 ft x 20 ft x 4 in2.47 cu yd2.72 cu yd7,300 to 7,600 lb
Decorative bedDecomposed granite12 ft x 12 ft x 3 in1.33 cu yd1.47 cu ydabout 4,250 lb
Metric pathAny5 m x 1 m x 6 cm0.30 cu m0.33 cu mvaries by material

Weights are estimates. Moisture and stone size change real weight, so confirm with your supplier.

Tips for a More Accurate Gravel Estimate

  • Pick the material first. Crushed stone suits driveways, drainage and sub-base, while pea gravel suits paths and play areas.
  • Measure the area that actually receives gravel, and split irregular areas into rectangles.
  • Match depth to the job: paths and decorative beds need less than driveways and drainage layers.
  • Keep the 10% waste allowance for compaction, then round up to the nearest whole unit when ordering.
  • Check your supplier's unit and density. If they sell by weight, use the weight result.

Frequently Asked Questions

How many cubic yards of gravel do I need for a driveway?

A typical two-car driveway (20×40 ft) at 4 inches deep requires (20 × 40 × 0.333) ÷ 27 = 9.9 cubic yards. Round up to 11 yards with a 10% waste allowance.

How much does a cubic yard of gravel weigh?

Crushed stone weighs approximately 2,700–2,800 lbs per cubic yard. Pea gravel is slightly lighter at around 2,500 lbs per cubic yard. Decomposed granite is denser at around 2,900 lbs per cubic yard.

Do I need landscape fabric under gravel?

Landscape fabric under decorative gravel helps prevent weeds and stops the gravel from mixing into the soil over time. For driveways and drainage applications, use a geotextile fabric designed for those applications instead.

Which gravel type should I choose for a driveway, path or drain?

Crushed stone such as #57 is angular and compacts well, so it suits driveways, drainage and sub-base. Pea gravel is smooth and comfortable underfoot, which suits paths and play areas. Decomposed granite packs into a firm surface for paths, and river rock is mainly decorative.

How much extra gravel should I order?

The calculator includes a waste allowance, with 10% a common choice to cover compaction, uneven ground and spreading losses. Always round up to the nearest whole unit your supplier sells.

Does the gravel calculator work in metric and imperial?

Yes. Use metres and centimetres, or feet and inches. The depth hints beside the field show typical values for driveways and pathways.