Crushed Stone Calculator

Crushed stone or crushed rock for driveways, bases and drainage: volume in cubic yards or m³, weight in tons or tonnes, and bulk bags.

Crushed stone is quarried rock broken into angular pieces. The sharp edges lock together when compacted, which makes it the usual choice for driveway bases, under slabs and pavers, and for drainage. It's sold by size: in the US, #57 stone (roughly 3/4 to 1 inch) is a common drainage and base stone; in the UK and Australia it's often sold as 20 mm crushed rock or, in Australia, blue metal. Enter the area and depth and this calculator gives the cubic yards or m³, the tons or tonnes, and the bags or bulk bags. A 12 × 10 ft base 4 inches deep is 1.48 cubic yards, about 2 US tons.

Units
Bag sizes
Area
ft
ft
in
Feet and inches work too: type 12'6 or 12.5.
t/yd³
%
Volume
1.56 yd³

42 ft³ · 1.189 m³

Weight
2.1 tons

4,200 lb · 1.91 tonnes

Bags
84

0.5 ft³ bag

Bags needed by size
0.5 ft³ bag84
25 kg bag77
20 kg bag96
850 kg bulk bag3
1 tonne bulk bag2
How it was worked out
  1. Area: 12 ft × 10 ft = 120 ft²; × 4 in (0.333 ft) deep = 40 ft³
  2. 40 ft³ ÷ 27 = 1.48 yd³
  3. Plus 5% extra = 1.56 yd³
  4. 1.56 yd³ × 1.35 tons per yd³ = 2.1 tons (4,200 lb)
  5. 42 ft³ ÷ 0.5 ft³ per bag = 84, rounded up to 84 bags
Typical weights of common materials
Materialt/m³tons/yd³lb/ft³
Concrete2.402.02150
Gravel1.601.35100
Pea gravel1.601.35100
Crushed stone / crushed rock1.601.35100
River rock1.501.2694
Landscape rock / pebbles1.501.2694
Crushed limestone1.601.35100
Decomposed granite1.501.2694
Crusher run1.601.35100
Road base1.701.43106
Crusher dust1.501.2694
Aggregate (20 mm)1.601.35100
All-in ballast1.651.39103
MOT Type 1 sub-base1.801.52112
Sand1.601.35100
Topsoil1.301.1081
Garden soil1.301.1081
Fill dirt1.401.1887
Mulch0.350.2922
Bark chippings0.300.2519
Asphalt (compacted)2.321.96145

Loose, as-delivered figures; asphalt and concrete are as laid. Moisture, stone size and source change the real weight, so use your supplier's figure when you have it. Tons are US short tons (2,000 lb).

Common use cases

  • A compacted base under a concrete slab, shed or patio
  • Driveway stone and parking areas
  • Drainage stone for French drains, soakaways and behind walls
  • Backfill around pipes and footings

How to use

  1. Choose feet and inches or metres and millimetres, and the country whose bag sizes you want.
  2. Enter the length and width of the area, or switch the shape to a circle, triangle or a known area. Use Add another area for L-shapes and separate beds.
  3. Enter the depth of stone. Bases under slabs and pavers are often 4 to 6 inches (100 to 150 mm).
  4. Check the density and the extra allowance. Change the density if your supplier quotes a different figure.
  5. Read the volume, weight and bag count, and add a price per ton, cubic yard, m³ or bag for a cost estimate.

FAQ

How much does crushed stone weigh?

Typically around 1.35 to 1.5 US tons per cubic yard (1.6 to 1.8 tonnes per m³) loose, depending on the rock and the size. Stone with fines (dust) packs denser. The calculator starts at 1.6 t/m³; use your quarry's figure if you have it.

What size crushed stone should I use?

Larger stone (1 to 2 inches, 20 to 40 mm) is common for driveway and drainage bases; stone with fines, which compacts hard, is used for the top of a base; and clean stone without fines drains best. Ask your supplier what they sell for the job, as names and sizes vary by region.

How much extra should I order for compaction?

Clean stone compacts only a little, so 5 to 10% is usually enough. Stone with fines, such as crusher run, can compact by 15 to 20% or more; use the crusher run calculator, which allows for that.

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