UK paving sand calculator
Paving Sand Calculator UK
Estimate paving sand for a bedding layer under slabs or block paving. Use the product and installer guidance for the exact bed depth, then use this page to convert area into cubic metres and tonnes.
Quick answer
- 20 m2 at 25 mm needs about 0.55 m3 after 10% allowance.
- 20 m2 at 30 mm needs about 0.66 m3 after 10% allowance.
- 20 m2 at 50 mm needs about 1.10 m3 after 10% allowance.
Paving sand estimates for 20 m2
| Area | Bedding depth | Cubic metres | Tonnes | Use case |
|---|---|---|---|---|
| 20 m2 | 25 mm | 0.55 m3 | 0.88 t | Thin bedding estimate |
| 20 m2 | 30 mm | 0.66 m3 | 1.06 t | Slab or paving bed |
| 20 m2 | 50 mm | 1.10 m3 | 1.76 t | Block paving bed |
Assumes 10% allowance and 1.6 tonnes per cubic metre sand density.
Interactive estimator
Bedding Sand calculator
Example 10x10 patio: bedding sand is about 0.34 cu yd or 19 half-cubic-foot bags.
Use the calculator to adjust sand depth, waste allowance, and bag size before ordering.
Sand and cement calculator paving notes
Some slab installations use a sand and cement bedding mix rather than a loose sand bed. This page estimates the sand volume only, so always follow the slab or paving manufacturer's bedding instructions.
For block paving, the bedding layer is normally sharp sand or grit sand over a compacted MOT Type 1 sub-base.
Avoid over-thick paving sand
A thick sand layer can settle. If the paving level is low, adjust the sub-base first and keep the bedding layer consistent.
Use the UK sub-base pages when you need MOT Type 1 or compactable aggregate below the sand.
Helpful next step
Use the block paving sand calculator for a 50 mm bedding layer, or the main sand calculator when your paving product specifies a different depth.