Paver Calculator for Patios
A paver calculator for a patio counts units from the face of the paver plus the joint, then reports the base and the bedding sand as volumes. The base depth starts at 4 in and the sand at 1 in. Both are editable starting points for a patio, not a code minimum and not a manufacturer's specification. The base density starts at the typical loose-gravel figure on the gravel calculator. It is not a quarry certificate.
Last reviewed: 2026-10-28 · How we calculate
How we calculate
Area = length × width. Module = (paver length + gap) × (paver width + gap), in feet, or metres on the metric toggle. Pavers = area × (1 + waste %) ÷ module, rounded up. Base volume = area × base depth. Sand volume = area × sand depth. Kilograms = base volume × density, only when density is greater than zero. Depths are millimetres.
Worked example
The form’s 12 × 10 ft patio of 12 × 12 in pavers needs 130 pavers. The base is 1.48 yd³ and the bedding sand is 0.37 yd³.
Pavers, base, and bedding sand
A paver patio needs three materials that are easy to mix up: the pavers, the compacted base, and the bedding sand. This page counts all three from the same plan area. The joint sand that sweeps into a 3 mm gap is not the bedding sand. A 100 mm base and 40 mm of sand are starting depths for a garden patio. A driveway should not inherit them without a thicker base.
Measuring a paver patio
Patio pavers fail in the order when the joint is forgotten or the base is copied from a default. The module is the paver face plus one joint on each side, the same pattern as the tile calculator. A 200 mm by 100 mm paver with a 0 mm gap occupies 0.02 square metres, so a 4 square metre patio is 200 pavers before waste. A 3 mm joint makes the module 0.203 by 0.103, which is a slightly larger footprint and a slightly smaller count. Waste then adds the cuts. Ten percent on a straight grid is the number sitting in the field. A fan or a circle wastes more. Raise it. The count rounds up to a whole paver.
How the patio becomes pavers and base
Base and bedding are volumes of the full plan area. They do not shrink because the pavers have gaps, and they do not grow past the edge unless you lengthen the area. One hundred millimetres of base on 4 square metres is 0.40 cubic metres. Forty millimetres of sand is 0.16 cubic metres. Those two depths are on the form so a first look is not zero, and they are labelled as starting points. A footpath and a driveway are not the same build-up. Compacted thickness is less than loose thickness. If you need the loose volume you will shovel, increase the depth to the loose depth your supplier describes. This page will not invent a compaction factor.
Ordering pavers, gravel, and sand
Weight is optional because density is not a single number. Leave the field at 0 and order by the cubic metre. If you type 1,500, a 0.40 cubic metre base is 600 kg. The gravel page uses 1,500 as its editable default and tells you to check the supplier. You can type the same 1,500 here when you want the two pages to match, and you should still change it when the ticket says something else. A metric tonne is 1,000 kg. This page does not call that a short ton. Sand for the bed can be weighed the same way only if you reuse the density field, which is labelled as the base. If the sand density differs, weigh the sand as volume times the sand density yourself. Do not pretend one field is both.
Checking a paver order
A concrete slab under pavers is the slab calculator, not this base volume. Tile indoors is the tile calculator, which counts boxes. Edge courses, a manhole, and a curve are why the waste field exists. Measure the rectangle that contains the patio, then decide whether the waste percentage is enough for the curve or whether you should measure the curve as its own area. There is no price per paver. Take the count and the cubic metres to the yard.
Paver fields and starting values
Length starts at 12 ft. Room length in feet. Switch to m / cm for metres. Width starts at 10 ft. Room width in feet. Switch to m / cm for metres. Paver length starts at 12 in. Paver length in inches, or millimetres on the metric toggle. Paver width starts at 12 in. Paver width in inches, or millimetres on the metric toggle. Joint gap starts at 0.1 in. Joint between pavers in inches, or millimetres on the metric toggle. Waste allowance starts at 10 %. Cuts at the edges. A diagonal or a curved border needs more than a straight grid. The percentage is yours. Base depth starts at 4 in. Base depth in inches, or millimetres on the metric toggle. Bedding sand depth starts at 1 in. Bedding sand depth in inches, or millimetres on the metric toggle. Base density starts at 95 lb/ft³. 95 lb/ft³ is a typical loose-gravel base (about 1,500 kg/m³), the figure already stated on the gravel calculator. It is not a quarry certificate.
Pavers, base, and sand for a rectangular patio
Pavers are 200 × 100 mm with a 3 mm joint and 10% waste. Base depth is 100 mm and bedding sand is 40 mm. Weight is off because density is 0.
| Patio | Pavers | Base | Sand |
|---|---|---|---|
| 10×10 ft | 489 | 0.93 m³ | 0.37 m³ |
| 12×12 ft | 704 | 1.34 m³ | 0.54 m³ |
| 16×12 ft | 939 | 1.78 m³ | 0.71 m³ |
100 mm and 40 mm are editable starting depths, not a code section. Driveways are often thicker.
Common mistakes
- Treating 100 mm of base and 40 mm of sand as required. They are starting numbers to edit.
- Using a density you invented so the kilogram line is not zero.
- Forgetting the joint. A gap makes each paver occupy more plan area, so you need slightly fewer pavers.
- Counting bedding sand as joint sand. The sand volume is the bed under the pavers.
- Expecting a price per paver or per tonne.
- Using the tile calculator's box count for pavers that are sold singly. This page counts units.
Frequently asked questions
How many pavers do I need for a patio?
Divide the area, plus waste, by the area of one paver including its share of the joint. A 4 m² patio of 200 by 100 mm units with no gap and no waste is 200 pavers.
How much base do I need under pavers?
Area times the depth you are building. Replace the form’s base depth with your build-up.
How much sand goes under pavers?
Area times the bedding depth. Jointing sand is extra and is not in this volume.
How heavy is the base?
Only after you type a density. Leave it at 0 and the weight stays 0. A metric tonne is 1,000 kg.
Do I need edge restraints in the count?
No. Pavers, base, and bedding are the outputs. Restraints are a perimeter you measure separately.
Is this a structural base design?
No. It is geometry. A driveway, a wet site, or a manufacturer's guide can call for a different depth.