Construction & trade New Zealand
Sand Calculator New Zealand
Sand under pavers, in a sandpit or beneath a slab is needed in a precise depth, and it is heavy. Enter the area and depth to work out the volume and weight, so you can order the right amount and know whether your trailer can carry it.
Free, no signup Runs in your browser
A typical figure you can change. Ask your supplier for theirs.
Gives a rough cost.
Order about
—Volume before waste
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Weight
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Loads of your trailer
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Rough cost
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Surface area covered
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The working
How much sand do I need?
Multiply the area by the depth, add an allowance for waste and settling, and round up. A 4 m by 3 m area at 50 mm deep is 0.60 m³, and with 10% extra you should order 0.7 m³, which weighs about 1.1 tonnes. Dry sand weighs about 1.5 to 1.7 tonnes per cubic metre, and wet sand more.
Bedding sand for paving
Pavers usually sit on a base of compacted aggregate with about 25 to 30 mm of screeded bedding sand on top. Use a coarse, sharp sand rather than a fine one, since fine sand holds water and moves. Extra sand is needed for filling the joints between pavers after they are laid.
Sandpits and play areas
A sandpit needs washed, clean play sand at a depth of about 200 to 300 mm, and it should be covered to keep animals out and be topped up or turned over from time to time. Ask the supplier for play sand, which is washed and screened, rather than building sand.
For the base under a paved area, use the gravel calculator.
How this is calculated
The rule, step by step, so you can check any figure by hand.
area = length × width, or π × (diameter ÷ 2)² for a round areavolume = area × depth (in metres)volume to order = volume × (1 + waste ÷ 100), rounded up to 0.1 m³weight = volume to order × tonnes per cubic metreloads = volume to order ÷ the size of your trailer or truck, rounded up
Always measure the area and the depth carefully, and add the allowance for waste and settling. Dry sand weighs about 1.5 to 1.7 tonnes per cubic metre, and wet sand more. Weights are typical values: moisture, compaction and the source of the material all change them, so use your supplier's figure when you have it.
The volume is rounded up to the next tenth of a cubic metre because suppliers sell in whole or half loads. A small job may be cheaper by the bag or by the trailer load than as a delivered bulk order, so ask for prices both ways.
A worked example
A 4 m by 3 m area, 50 mm deep, 10% waste.
- Area12 m²
- Volume0.60 m³
- With 10% waste0.660 m³
- To order0.7 m³
- Weight1.1 tonnes
Order about 0.7 m³.
Ask your supplier whether they sell by volume or by weight.
Weight and delivery
Sand is heavy: a cubic metre can weigh more than 1.5 tonnes, and wet sand weighs more. Most small trailers are rated for less, so order in smaller loads or have it delivered in bulk.
What it leaves out
Uneven ground, compaction and the exact density of your material are not modelled. The weight uses a typical figure, and prices vary by region and supplier.
What this calculator does not do
- Level, even depth assumed
- Typical weights you can change
- Rounded up to 0.1 m³
- An estimate for ordering
Common questions
How much sand do I need?
Multiply area by depth, add waste and round up.
How do I convert cubic metres to tonnes?
Multiply by the weight per cubic metre; the tool uses a typical figure you can change.
How much extra should I order?
About 10%, more for uneven ground or settling.
Can I use a trailer?
Yes, but check its load limit, because sand is heavy.
Is the cost exact?
No. It is the volume times the price you enter.
Where these numbers come from
- Wolfram MathWorld — cuboid Volume of a box: length × width × height. Fixed formula, nothing to go out of date
- Wolfram MathWorld — cylinder Volume of a round area: π × radius² × depth
Method last reviewed 2026-10-28 This calculator uses fixed rules rather than rates that change, and its method is re-checked against the sources above at least once a year. Out of date? Tell us and we will fix it.
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