Sand Calculator

Sand Calculator

Estimate how much sand you need for paving bedding, sandpits, under-slab blinding, trench fill or screeds. Enter the area and depth and get the volume, the weight in tonnes or US tons, and the number of bags or bulk bags.

Volume, tonnes & bagsDry or damp sandMetric & imperialLast updated: November 2, 2026

Calculate sand

m
m
cm
Paver bedding 3–5 cm / 1–2 in · sandpit 30 cm / 12 in
%
Sand bedding compacts; allow 10%+

Sand calculation formula

Volume

V = L × W × depth × (1 + extra%)

Weight

Weight = V × density

Dry sand weighs about 1,600 kg/m³ (2,700 lb/yd³). Damp sand is heavier, around 1,900 kg/m³, because of the water it holds.

Bags

Bags = ⌈weight ÷ bag weight⌉

Uses 25 kg bags in metric and 50 lb bags in imperial. A bulk bag holds about 0.85–1 tonne.

Sand types and weights

SandTypical useDensityPer yd³
Building (soft) sandBricklaying mortar, plaster1.60 t/m³1.35 US tons
Sharp / concreting sandConcrete, screeds, paver bedding1.65 t/m³1.39 US tons
Damp sandAs delivered, uncovered1.90 t/m³1.60 US tons
Play sandSandpits1.50 t/m³1.26 US tons

Worked example: 5 m × 4 m patio, 5 cm sharp sand bedding

  1. Volume = 5 × 4 × 0.05 = 1.0 m³; +10% = 1.1 m³
  2. Weight = 1.1 × 1.65 = 1.82 tonnes
  3. That is 73 × 25 kg bags, or 2 bulk bags — bulk is far cheaper at this size

Frequently asked questions

How much does a cubic metre of sand weigh?

About 1.6 tonnes when dry and up to 1.9–2.0 tonnes when wet.

How much sand do I need for a sandpit?

For a 1.5 m × 1.5 m sandpit filled 30 cm deep: 1.5 × 1.5 × 0.3 = 0.675 m³, about 1 tonne of play sand or 41 × 25 kg bags.

How many bags of sand in a ton?

40 bags of 25 kg make one tonne; 40 bags of 50 lb make one US ton.

Results are estimates; sand density varies with grading and moisture.

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