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Calcumetryx

Materials

Gravel Calculator

How much gravel a driveway, path or pad takes — in cubic yards, cubic feet or cubic metres.

Gravel
Start from
Area shape

Beds, drives, pads, plots

Depth of the gravel layer itself. A drive usually wants more than a path, and a base course more than a top dressing.

Volume needed

Volume needed: 2.96 cubic yards

cubic yards

Rectangular prism
depth exaggerated for legibility
20 ft12 ft4 in
Cubic feet
80cu ft
Cubic metres
2.27
Area covered
240ft²
Weight
tonsAdd a density to get tons. Your supplier has the figure for the exact product.

The working

  1. Area = Length × Width

    = 20 ft × 12 ft

    = 240 ft²

  2. Volume = Area × Depth

    = 240 ft² × 0.333 ft

    = 80 cu ft

  3. Cubic yards = Cubic feet ÷ 27

    = 80 ÷ 27

    = 2.96 cu yd

    1 cubic yard = 3 ft × 3 ft × 3 ft = 27 cubic feet

Enter the area and how deep you want the stone. You get the volume immediately; tons only appear if you supply a density, because gravel weight depends on the stone and how wet it is, and no honest single figure covers every product.

How this calculator works

Specification
Formula version
1.0.0
Last reviewed
2026-09-01
External data
None

This tool uses only your inputs and exact unit conversions. No benchmark, average or market figure is built into it. How we calculate

What this calculates

The volume of stone needed to cover an area to a chosen depth, in cubic yards and the metric and imperial equivalents. That volume is what a supplier quotes and delivers against.

The arithmetic

Area times depth, converted to cubic yards by dividing the cubic feet by 27. A circular area uses π × diameter² ÷ 4. Every entry is converted to feet before anything is multiplied, so you can measure the length in metres and the depth in inches and the result is still right.

Why tons need a density from you

Gravel is sold by volume in some yards and by weight in others, so the conversion matters. But it depends on the stone size, how angular it is, and how much water it is carrying — a wet load can weigh appreciably more than a dry one of the same volume.

Rather than bake in an average that would be wrong for most products, this calculator leaves the density field empty and asks your supplier for the figure. Enter it and the tonnage appears; leave it and the volume answer is unaffected.

Depth in layers

A drive or pad is normally built up in courses — a coarser base beneath a finer surface — rather than as one deep layer of a single product. Run the calculator once per course, at that course's own depth, and order each separately.

Worked example

A 40 ft × 12 ft driveway, 4 in deep

Given
Length
40 ft
Width
12 ft
Depth
4 in
Step by step
  1. Depth in feet= 4 in ÷ 12= 0.333 ft
  2. Area= 40 ft × 12 ft= 480 sq ft
  3. Volume= 480 sq ft × 0.333 ft= 160 cu ft
  4. Cubic yards= 160 ÷ 27= 5.93 cu yd
Order5.93 cubic yards
What it assumes
  • Constant depth across the whole area, with vertical edges.
  • The volume is the neat geometric volume of the finished layer, before any compaction.
  • Unit conversions are exact (1 in = 25.4 mm, 1 cubic yard = 27 cubic feet).
  • Density and price are used only if you enter them.
What it does not do
  • It does not assume a density, so it cannot give tons on its own.
  • It does not apply a compaction factor. Stone consolidates under traffic and rolling, and the allowance for that varies by product and specification.
  • Irregular areas have to be split into rectangles and circles and added together.

Common questions

How many tons of gravel is a cubic yard?
It depends on the product, so this calculator will not guess. Ask your supplier for the density of the exact stone you are buying, enter it, and the tonnage appears alongside the volume. Stone size, angularity and moisture all move the figure.
How deep should gravel be for a driveway?
Deeper than a path, and normally built in layers rather than one lift. Run this calculator once per layer at that layer's depth. Under about two inches, gravel tends to scatter and let the subgrade show through.
Does this work for pea gravel and crushed stone?
Yes — the geometry is identical for any loose aggregate. Only the density differs, and that is the figure you supply.

Found a problem?