Paver Calculator

How many pavers do I need? The arithmetic behind the count

Every paver order starts from one division: patio area divided by the area of a single paver, then padded for the pieces you will cut and break. Because paver sizes are quoted in inches and patios are measured in feet, the cleanest way to do it is to convert everything to square inches. Multiply length by width in feet, multiply by 144 to get square inches, divide by the paver's own square inches, multiply by one plus the waste factor, then round up. Rounding up matters: half a paver is not a thing you can order.

Worked example: a 12 ft by 10 ft patio in 4 x 8 in Holland pavers

The patio is 120 square feet, or 17,280 square inches. A 4 x 8 in Holland paver covers 32 square inches, so the bare count is 17,280 / 32 = 540 pavers. At the standard 10 percent waste allowance that becomes 594, and if you are laying a 45-degree herringbone you would use 15 percent instead and order 621. At 0.65 per paver, 594 pieces is about 386 in materials for the surface alone.

The same patio in 12 x 12 in slabs needs 17,280 / 144 = 120 slabs before waste, 132 with the 10 percent margin. Fewer, larger units mean fewer joints and a faster lay, but each cut wastes far more surface area, which is exactly why the waste percentage is a separate input rather than something baked into the count.

The base and bedding layers for the same patio

Under those pavers sits the part nobody photographs and everybody underestimates. The standard patio cross-section from the top down is: pavers 2 3/8 in thick, 1 in of coarse bedding sand, 4 in of compacted crushed gravel base, geotextile fabric, then compacted subgrade. For 120 square feet, the gravel works out to 120 x (4/12) / 27 = 1.48 cubic yards, roughly 2 tons of crushed stone. The bedding sand is 120 x (1/12) / 27 = 0.37 cubic yards, about half a ton. Total excavation depth is around 7 1/2 in below the finished paver surface.

A driveway changes only one number, but changes it a lot: the gravel goes to 6 to 8 in, so the same footprint would need 2.2 to 3.0 cubic yards instead of 1.48. Freeze-thaw climates in the northern US, Canada and much of the UK justify the deeper end even for a patio, and heavy clay subsoil justifies it always.

Waste allowance by pattern

Do not forget the edge restraint

Pavers laid on sand have nothing holding the perimeter together. Without a plastic or aluminium edge restraint spiked into the base every 10 to 12 in, the outer courses creep outward, the joints open, and the field loosens from the edges inward over two or three seasons. Measure the perimeter in linear feet — for the 12 x 10 example that is 44 ft, minus any side that butts a house wall — and buy edging plus about 4 spikes per foot of restraint. This calculator does not size that for you, but it is a small line item that decides whether the patio still looks square in year five.

Joint sand is a third material

Bedding sand goes under the pavers; joint sand goes between them. They are different products, and the volume above covers only the bedding layer. For 4 x 8 in pavers, plan on roughly one 50 lb bag of polymeric sand per 75 to 100 square feet, so two bags for the example patio. Large-format slabs need far less because there is less joint length per square foot. Sweep it in dry, compact the field with a plate compactor over a protective mat, top the joints up, then mist to activate.

What this calculator does not account for

It works from nominal paver dimensions and assumes tight sand-set joints, which is how interlocking concrete pavers are normally laid. If you are laying flagstone or slabs with deliberate 1/2 in mortar or gravel joints, add the joint width to each paver dimension using the custom size fields before calculating — a 12 in slab with a 1/2 in joint behaves like a 12.5 in unit and your count drops by about 8 percent. The maths also assumes a rectangle. For an L-shape, split it into rectangles and run each one; for a circle, use pi times the radius squared as the area and enter equivalent dimensions. Slope, steps, and inlaid borders in a contrasting colour all shift the count, and pavers vary between manufacturers even at the same nominal size, so confirm against the coverage figure printed on the pallet before you place the order.