Paver Calculator
How many pavers for a patio or path, with the base gravel and bedding sand beneath them, by volume and weight.
Result…
How it's calculated
Pavers = area × (1 + waste %) ÷ ((paver length + gap) × (paver width + gap)), rounded up Base gravel = area × base depth; weight = volume × density Bedding sand = area × sand depth; weight = volume × density
Counts the pavers for a rectangular patio, path or drive, or any area you already know, allowing for the joint between them and extra for cuts and breakage. It also works out the base gravel (sub-base) and the bedding sand to go under them from the depths you plan, as volumes and as weights at the densities you enter, since suppliers sell by either. Base and bedding depths depend on the ground, the paver and the traffic, so take them from the paver maker's guide or your designer. For gravel on its own, use the gravel calculator.
Your numbers, step by step
About the Paver calculator
This paver calculator counts the block pavers or slabs for a patio, path or drive, and works out the base gravel and bedding sand that go underneath. Enter the length and width of the area, or the area itself, the paver size and the joint gap, and a waste allowance for cuts and breakage. Each paver is counted with its share of the joint, so narrow gaps on small pavers are not ignored. Then enter the base and sand depths from your design or the paver maker's guide, and the densities your supplier gives, to see volumes in cubic metres or cubic yards and weights in tonnes or US tons. Every density and depth is yours to change, and the steps show the working with your own numbers. For a gravel path or drive with no pavers on top, use the gravel calculator.
How to use it
- Choose metric or imperial units, then enter the “Length” and “Width”, or switch “I know the” to “Area”.
- Enter the “Paver length”, “Paver width” and “Joint gap”.
- Set the “Extra pavers for waste”, allowing more for curves and herringbone.
- Enter the “Base gravel depth” and “Bedding sand depth” you plan, or 0 for none.
- Check the “Gravel density” and “Sand density” with your supplier and read the pavers, volumes and weights.
Worked example
A 4 × 2.5 m patio is 10 m². A 200 × 100 mm paver with a 3 mm joint covers 203 × 103 mm = 0.020909 m², so there are about 47.83 pavers per m². With 5% extra, 10 × 1.05 ÷ 0.020909 = 502.18, so buy 503 pavers. A 100 mm base is 10 × 0.1 = 1 m³ of gravel, 1.6 t at 1.6 t/m³, and a 30 mm sand bed is 0.3 m³, or 0.48 t.
Updated
Questions people ask
How many pavers do I need per square metre?
Divide 1 by the area of one paver including its joint. For a 200 × 100 mm paver with a 3 mm gap that is 1 ÷ (0.203 × 0.103), about 47.83 per m². In imperial, divide 144 by (length + gap) × (width + gap) in inches for pavers per square foot.
How deep should the gravel base be under pavers?
It depends on the ground, the paver and the load: a drive for cars needs a deeper, well-compacted base than a garden path. Follow the paver manufacturer's laying guide or a designer for your site, and enter that depth here.
How much bedding sand goes under pavers?
Multiply the paved area by the depth of the sand course. The calculator gives the volume and, at the density you enter, the weight to order. Damp sand weighs more, so ask your supplier which figure to use.
Should I include the joint gap when counting pavers?
Yes. Each paver plus its gap is the unit that repeats across the patio, so leaving the gap out slightly overstates the count. Enter 0 for pavers with built-in spacer nibs that are laid touching.
What does this paver estimate leave out?
It treats the area as one rectangle or one area figure, so curved edges, steps and patterns need a bigger waste allowance. It also uses compacted depths, and loose gravel and sand settle when compacted, so order a little extra or follow your supplier's advice.