Paver Calculator

Paver counting is deceptively simple, patio area divided by the area one paver occupies. The trap is that a paver occupies more than its own footprint. It also takes half a joint on each side, so a 4 × 8 inch paver with an eighth-inch joint really covers 4.125 × 8.125.

On a small patio that difference is a handful of pavers. On a large one with wide joints it is a pallet.

The base is a separate calculation and uses the same 324 constant that governs every bulk landscape material, square feet times depth in inches, divided by 324, gives cubic yards. Base depth is the thing most DIY patios get wrong, and it is the only part you cannot fix later.

1. Step 1 Patio area area = length × width
2. Step 2 Area one paver occupies paver_area = (paver_L + gap) × (paver_W + gap) ÷ 144 Divide by 144 to convert square inches to square feet.
3. Step 3 Paver count with cutting waste pavers = ceil(area ÷ paver_area × (1 + waste%)) 10% is standard; 15% for herringbone, diagonal layouts or curved edges.
4. Step 4 Or in metric paver_area_m² = (L_cm + gap) × (W_cm + gap) ÷ 10,000 The same sum without the 144, because metric units already nest in powers of ten.
5. Step 5 Gravel base and bedding sand cubic_yards = area × depth_inches ÷ 324, or cubic_metres = area_m² × depth_cm ÷ 100
6. Step 6 Joint sand and edging poly_sand_bags = ceil(area ÷ 100) edging = perimeter of the patio

For example, a 12 × 10 ft patio is 120 square feet. A 4 × 8 in paver with 1/8 in joints occupies 0.233 sq ft, so you need 516 pavers, or 568 with 10% waste. The base at 4 inches is 1.48 cubic yards of gravel plus 0.37 of sand.

• Pavers are assumed to be laid in a running bond or stack pattern. Herringbone at 45 degrees needs closer to 15% waste because every perimeter paver is a diagonal cut.
• The nominal paver size is used. Manufacturers usually make pavers a fraction under nominal so that with a standard joint they lay out on a clean module, using the nominal figure with a joint added is the conventional way to count.
• Polymeric sand is estimated at one 50 lb bag per 100 square feet, which suits joints of about an eighth of an inch on standard pavers. Wide joints, large-format slabs or permeable pavers use considerably more.
• Gravel base depth defaults to 4 inches, which suits a patio or walkway on stable, well-drained soil. Clay soils, driveways and hard-freeze climates need 6 to 12 inches, and that judgement is site-specific.
• The base volume is the compacted depth. Crushed stone compacts by roughly 20%, so order about 20% more loose material than the figure shown, or specify compacted yardage with your supplier.
• Bedding sand is 1 inch screeded flat. This is a levelling layer only; using sand to correct base depth is the most common cause of settling.
• Edging is the patio perimeter. Curved edges and steps need more, and any edge against a house wall or existing hard surface needs none.
• Excavation depth is not calculated. Total dig is base depth plus sand depth plus paver thickness, which for a typical patio is around 9 inches.
• The paver size presets are US formats. In metric mode the standard European block paver of 200 × 100 mm is the Custom option with 20 and 10 entered, and the joint drops to about 3 mm for a sand-set laying course.