Sand Calculator
Sand under pavers, in screeds or in a sandpit is ordered by weight and spread by volume. This sand calculator converts your area and depth into cubic metres, tonnes and 25 kg bags.
Density is set to 1.6 t/m³ (1.35 tons/yd³) for damp construction sand. Kiln-dried sand is lighter (~1.4 t/m³); wet sand is heavier (~1.9 t/m³).
Enter valid values to see the results.
Formula
Convert depth to metres (5 cm = 0.05 m) before multiplying. Imperial: cubic feet ÷ 27 = cubic yards, × 1.35 = short tons.
How to measure
- Measure length × width of the area to be filled.
- Typical depths: 3–5 cm bedding layer under pavers, 5 cm for screed over insulation, 20–30 cm for a children’s sandpit.
- For mortar and concrete sand, use the Cement Calculator instead — it splits the mix for you.
Worked example
Practical tips
- Use sharp (washed) sand under pavers and in screeds; soft building sand holds moisture and shifts.
- Screed the bedding layer with rails and a straight edge — paver level depends on it.
- Do not compact the bedding sand before laying pavers; compact everything together after laying.
- Cover delivered sand: rain adds 10–20% weight and makes screeding impossible.
Waste allowance
Add 5–10% for levelling losses and uneven subgrade. Sand compacts about 10% under plate compaction.
Sand depth by application
| Application | Metric | Imperial |
|---|---|---|
| Paver bedding | 3–5 cm | 1–2 in |
| Floor screed | 5 cm | 2 in |
| Pool base | 5 cm | 2 in |
| Sandpit | 20–30 cm | 8–12 in |
Common mistakes
- 1 Using building (soft) sand under pavers — it retains water and the surface becomes uneven.
- 2 Compacting the bedding layer before laying pavers, which makes height adjustment impossible.
- 3 Ordering dry-sand tonnage for wet delivery — wet sand weighs up to 20% more per cubic metre.
- 4 Forgetting edging: without a border, bedding sand and pavers migrate sideways.
Frequently asked questions
How many tonnes of sand in a cubic metre?
About 1.6 tonnes for damp construction sand, 1.4 t for kiln-dried and up to 1.9 t for wet sand.
How much sand under pavers?
A 3–5 cm bedding layer: for 10 m² that is 0.3–0.5 m³, or 0.5–0.8 tonnes. Add 10% for levelling.
How much sand do I need for a sandpit?
A 1.5 × 1.5 m sandpit at 25 cm deep needs 0.56 m³ ≈ 0.9 tonnes — about 36 bags of 25 kg of washed play sand.
What area does 1 tonne of sand cover?
About 12.5 m² at 5 cm depth or 6 m² at 10 cm (at 1.6 t/m³).
Can I use this for mortar sand?
For mortar, use the Cement Calculator — it splits cement and sand by mix ratio. This calculator is for bulk fill and bedding layers.