Paver Sand Calculator
Find how much sand goes under and between pavers: the sharp sand bed and the kiln-dried sand for the joints.
Measure your project
Your answer
That is 1.00 m³.
If you buy bags
If you buy bulk bags
This is the sand bed only. The joints need kiln-dried sand too (see below). For a drive, check your local building rules or ask a builder or engineer.
What it costs
Sharp sand: £75 a bulk bag with VAT, the middle of only 3 UK sellers (Oct 2026). Treat it as a rough guide. Jointing sand is not in this sum.
Quick answers
- A 5 × 4 m patio, 50 mm bed
- About 1.51 tonnes of sharp sand, or 2 bulk bags of 800 kg. Add about 5 large bags of kiln-dried sand for the joints.
- How thick is the sand bed
- Interpave says 50 mm once packed down. Marshalls' trade guide says 30 mm once packed down. Marshalls' DIY guide spreads 50 mm, then packs it.
- Sand per m²
- About 76 kg for a 50 mm bed, or 45 kg for 30 mm.
- Sand for the joints
- One large bag of kiln-dried sand covers about 4–5 m², say Wickes and B&Q.
How to work it out
- Measure the area to be paved in metres. Length × width = m².
- Pick the thickness of the sand bed in mm. Divide it by 1,000 to get metres.
- m² × thickness in metres = m³ of sharp sand for the bed.
- Sharp sand weighs about 1.51 tonnes per m³. So m³ × 1.51 = tonnes. Divide by 0.8 for 800 kg bulk bags.
- For the joints, divide the m² by 4. That gives large bags of kiln-dried sand. Round both up.
5 × 4 = 20 m²
20 × 0.05 = 1 m³ × 1.51 = 1.51 tonnes → 2 bulk bags
Joints: 20 ÷ 4 = 5 large bags
How much sand under pavers: common sizes
Block paving (pavers) needs two kinds of sand. Sharp sand makes the bed under the blocks. Fine, kiln-dried sand fills the joints between them.
This table shows both for common patio, path and drive sizes.
| Size | Bed, 50 mm | Bed, 30 mm | Kiln-dried bags |
|---|---|---|---|
| 3 × 3 m | 0.68 t · 1 bag | 0.41 t | 2–3 |
| 4 × 3 m | 0.91 t · 2 bags | 0.54 t | 3 |
| 5 × 4 m | 1.51 t · 2 bags | 0.91 t | 4–5 |
| 6 × 4 m | 1.81 t · 3 bags | 1.09 t | 5–6 |
| 8 × 5 m | 3.02 t · 4 bags | 1.81 t | 8–10 |
| 10 × 6 m | 4.53 t · 6 bags | 2.72 t | 12–15 |
Bulk bags of 800 kg. Kiln-dried bags at 4–5 m² each. Nothing extra added.
Bedding sand under pavers: 50 mm or 30 mm?
UK guides give two thicknesses for the bed of sand, called the laying course.
- 50 mm: Interpave, the UK paving makers' group, once packed down. Marshalls' DIY guide also spreads 50 mm before packing. That is about 76 kg of sand per m².
- 30 mm: Marshalls' guide for trade layers, once packed down. It allows 25–40 mm. That is about 45 kg per m².
The calculator starts at 50 mm, the thicker of the two. Ask your supplier or the block maker which one to use.
Compacting the sand before laying pavers
Marshalls says to pack the sand down first, then lay the blocks. Its DIY guide gives these steps:
- Spread a 50 mm layer of damp sharp sand.
- Pack it down with a vibrating plate (a plate compactor).
- Level it, leaving it 3–5 mm higher than you need. The blocks press down into it.
- Lay the blocks.
- Brush kiln-dried sand into the joints. Run the plate over it, then brush in more until the joints are full.
Tips from Marshalls' trade guide
- Use grit (sharp) sand, not building sand. Don't add cement.
- The sand should be damp, but not soaking wet.
- Build the slope into the stone base, not the sand.
- Cover any sand you leave open overnight.
Sand between pavers: kiln-dried jointing sand
Wickes says one large bag of kiln-dried sand covers about 4 m² of normal block paving. B&Q sells a similar bag as covering 5 m².
| Area | Bags | Cost |
|---|---|---|
| 5 m² | 1–2 | £8–£16 |
| 10 m² | 2–3 | £16–£24 |
| 20 m² | 4–5 | £32–£40 |
| 30 m² | 6–8 | £48–£64 |
| 50 m² | 10–13 | £80–£103 |
At £7.95 a bag with VAT. The higher count uses 4 m² a bag.
Prices with VAT: £7.90 at Wickes and £7.95 at B&Q. That is only 2 shops. A 25 kg bag from an online seller on B&Q's site was £17.99, about twice as much.
Thicker blocks take more sand. Marshalls gives the cover for each block thickness:
| Block thickness | Area per bag | Sand per m² |
|---|---|---|
| 50 mm | 6–8 m² | 3.1–4.2 kg |
| 60 mm | 4.5–6.5 m² | 3.8–5.6 kg |
| 80 mm | 3.5–5.5 m² | 4.5–7.1 kg |
Sand per m² is our sum from Marshalls' figures.
Under the sand: the paver base for a patio, path or drive
The sand bed sits on a base of crushed stone, called the sub-base. Interpave gives 100–200 mm of sub-base for drives, paths and patios. Weaker ground needs the deeper end.
Using MOT Type 1 for the base? Our Type 1 calculator gives the tonnes.
A drive carries the weight of cars. Check your local building rules or ask a builder or engineer.
Questions people ask
How much paver sand do I need?
For the bed: m² × thickness in metres × 1.51 = tonnes of sharp sand. A 5 × 4 m patio at 50 mm takes about 1.51 tonnes. Its joints take about 5 large bags of kiln-dried sand.
How deep should the sand be under pavers?
Interpave says 50 mm deep once packed down. Marshalls' guide for trade layers says 30 mm once packed down. The sources don't agree, so ask your supplier.
Do you need to compact sand before laying pavers?
Yes, says Marshalls. Pack the damp sand down with a vibrating plate. Then level it 3–5 mm higher than you need, and lay the blocks on top.
Do you need to put sand under pavers?
For block paving, yes. Interpave's guide puts the blocks on a sand bed, over a stone sub-base. Patio slabs are laid another way: see our sand calculator.
How much sand do I need for the joints between pavers?
Wickes says a large bag of kiln-dried sand fills the joints of about 4 m² of block paving. B&Q says 5 m². So 20 m² takes 4–5 bags.
What sand goes under block paving?
Sharp sand, also called grit sand. Marshalls says not building sand, and no cement. The sand should be damp, not soaking.
How many bags of paver sand do I need?
In small bags of 22.5 kg, a 50 mm bed takes 4 bags per m². A 5 × 4 m patio takes 68. Bulk bags are easier for a big job.
How much does paver sand cost?
Sharp sand is about £75 a bulk bag with VAT, from only 3 sellers. Kiln-dried sand is £7.90–£7.95 a large bag with VAT, at Wickes and B&Q.
Where our numbers come from
- Interpave, Concrete Block Paving guide
- Compact the sand bed first: Marshalls how to lay block paving
- Block paving sand bed 30 mm packed down: Marshalls trade guidelines
- Kiln-dried sand large bag: Wickes £7.90 inc VAT (about 4 m²)
- B&Q: Tarmac paving sand large bag
- Kiln-dried sand 25 kg, B&Q marketplace seller, £17.99 inc VAT
- Marshalls Joint Filling Sand data sheet (2024)
- Sand weight: Wickes sharp sand bulk bag (800 kg covers 10.6 m² at 50 mm)
- Small bags: Wickes Major Bags (22.5 kg sand, 22.5 kg gravel)
- Type 1 weight and price: Wickes 800 kg bag (checked Oct 2026)
- Mainland Aggregates: 850 kg bulk bags
- Bulk bag prices: the middle price from 3 UK sellers each (Wickes, Tippers, Lawsons; Oct 2026)
Made by BuildersCount. Last checked 4 Oct 2026.
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