Sand Calculator

How it is calculated

The area is treated as a rectangle filled with a flat layer of sand. Length and width are in metres, depth is in centimetres and density is in kg per m³. Volume is V = length × width × (depth ÷ 100) in m³. Weight is kg = V × density, shown in tonnes as kg ÷ 1000. The bag count is ⌈kg ÷ 25⌉, because the tool always uses 25 kg bags and rounds up to whole bags. All four fields are required and must be above zero. Depths above 300 cm and densities outside 500 to 3,000 kg/m³ give no result, since real sand layers and sand densities fall well inside those limits. The density you enter decides the weight: dry, damp and compacted sand differ, so use the figure for your material. No allowance is made for compaction or spillage, so for a bed that will be compacted, order a little more.

Common mistakes

• Entering the depth in metres or millimetres. The field is centimetres, so 0.05 gives almost nothing and 50 for a 5 cm layer gives ten times too much.
• Entering density in g/cm³ or t/m³, for example 1.6. The field is kg per m³, and a value below 500 shows no result; type 1600.
• Using one density for every state of the sand. Wet sand is heavier per cubic metre than dry sand, so the bag count changes with the density you type.
• Expecting a different bag size. The bag count always assumes 25 kg bags, so with 20 kg bags divide the weight yourself.
• Forgetting compaction under pavers or in a trench. Loose sand settles when it is compacted, so the calculated amount can leave the layer thinner than planned.