Give the patio’s shape and size and the paver you like. You get how many pavers to buy with the cuts, the gravel base and bedding sand in yards and bags, the edging, how deep to dig and the slope to drain it.
Pavers to buy
681 pavers, 4 × 8″144 sq ft + 5% for cuts · 113 bags of paver base · 24 bags of sand · 48 ft of edging
Quick answer: a 12 × 12 ft patio of 4 × 8″ pavers takes 681 pavers: 648 for its 144 sq ft plus 5% for cuts (10% for a circle or herringbone). Under them go 4–6″ of compacted gravel run 6″ past the edges, 1″ of bedding sand, and an edge restraint all round. Dig deep enough for the pavers and both layers, 7⅜″ (Belgard says at least 8″), and slope the top 2% away from the house.
How to use the paver patio calculator
- Pick the shape and enter its length and width, or a circle’s diameter.
- Enter the paver’s face as the maker names it: 4 × 8, 6 × 9, 12 × 12, 16 × 16.
- Pick the base: 4″ on well-drained soil, 6″ on clay or where the ground freezes.
- Pick the pattern, and say if one side is against the house.
The rules behind the numbers
Pavers and cuts
Oregon State University Extension’s 10-step guide: take the patio’s square footage, then “You should always add 5% to this figure, to allow for the pavers that will be cut to fit curves and odd spaces. If you know that you will be cutting a lot of pavers, you should add 10%.” A circle, or a herringbone laid at an angle, cuts pavers at every edge, so the calculator adds 10%.
The base
Unilock: “The guidelines are 4 to 6 inches for pedestrian walkways and 8 to 12 inches for driveways”, and “the base material should extend past the paved edge an equal distance of the base depth”. Belgard’s installation guide: “Add 4-8″ of base material compacting in 2-4″ lift thickness increments” and “over excavate a minimum of 6″ beyond the perimeter”.
The sand and the edge
Belgard: “Add nominal 1″ uncompacted bedding sand layer and screed to level. Use concrete sand. Masonry sand, screenings or stone dust should never be used.” Then “Install paver edge restraint”: spiked plastic, steel or aluminum edging, or a concrete curb.
The dig and the slope
Oregon State adds the base, the 1″ of sand and the paver’s thickness; Belgard’s guide says to “Excavate area a minimum of 8″ below finished grade” and to “Confirm final surface slope is ≥ 2%”. Unilock calls 1–2% adequate. Belgard’s Holland Stone is 4 × 8 × 2⅜″.
Pavers and materials for common patio sizes
| Patio | 4 × 8″ pavers (+5%) | 4″ gravel base | Sand (0.5 cu ft bags) | Edging |
|---|---|---|---|---|
| 10 × 10 ft | 473 | 1.49 cu yd | 17 | 40 ft |
| 12 × 12 ft | 681 | 2.09 cu yd | 24 | 48 ft |
| 12 × 16 ft | 908 | 2.73 cu yd | 32 | 56 ft |
| 16 × 20 ft | 1,512 | 4.41 cu yd | 54 | 72 ft |
| 20 × 20 ft | 1,890 | 5.44 cu yd | 67 | 80 ft |
The base runs 6″ past every edge. Bags are Quikrete’s 0.5 cu ft Paver Sand; its 50 lb bags make the 12 × 12 patio’s sand 1,200 lb.
Pavers per square foot
| Paver | Per square foot |
|---|---|
| 4 × 8″ (brick, Holland) | 4.5 |
| 6 × 6″ | 4 |
| 6 × 9″ | 2.67 |
| 12 × 12″ | 1 |
| 16 × 16″ | 0.56 |
| 12 × 24″ | 0.5 |
By the size the maker names, which counts the joint. A maker’s sheet prints its own pieces per square foot: use it when it differs.
Four worked examples
A 12 × 12 ft patio of 4 × 8 pavers. 681 pavers, 2.09 cu yd of gravel base (113 bags), 24 bags of sand and 48 ft of edging.
A 12 × 16 ft patio against the house. 908 pavers; the edging skips the house side, 40 ft, and the base stops at the wall: 2.62 cu yd.
A 10 ft round fire pit patio. 79 sq ft plus 10% for all the edge cuts: 389 pavers and 31.4 ft of flexible edging.
A 10 × 20 ft patio of 12 × 12 slabs on clay. 210 slabs on a 6″ base: 4.28 cu yd, dug 9⅜″ deep.
Common paver patio mistakes
- Buying the exact count. Cut pavers are waste: add 5%, or 10% for curves and herringbone.
- A base the size of the patio. Run it at least 6″ past every edge, or the edges sink.
- Too much sand. 1″, screeded; sand is not a leveller for a bad base.
- No edge restraint. Without it the pavers creep apart.
- A flat patio. Slope it 2% away from the house: about ¼″ a foot.
Measuring an odd-shaped patio? The free square footage calculator adds up any shape. The Rate My Backyard tool scores the yard around it, and the 2D planner lays out the furniture.
Measure an odd shapeRead next
Paver patio questions
How many pavers do I need?
The patio’s square feet times the pavers per square foot, plus 5% for cuts (10% for a circle or herringbone). A 12 × 12 ft patio of 4 × 8″ pavers: 144 × 4.5 = 648, plus 5% = 681.
How do I use a paver calculator?
Enter the patio’s length and width (or a circle’s diameter) and the paver’s face size. It returns the pavers with the cut allowance, the base, the sand and the edging.
How much paver base do I need?
4–6″ of compacted gravel for a patio (Unilock), run 6″ past the edges. A 12 × 12 ft patio at 4″ takes 2.09 cu yd, or 113 of Quikrete’s 0.5 cu ft bags.
How much sand for pavers?
A 1″ bedding layer (Belgard) over the paved area: 12 cu ft for a 12 × 12 ft patio, 24 bags of 0.5 cu ft, about 1,200 lb at Quikrete’s 50 lb a bag. Joint sand is extra.
How deep do I dig for a paver patio?
The base, 1″ of sand and the paver: 4 + 1 + 2⅜ = 7⅜″ for a 2⅜″ paver on a 4″ base. Belgard’s guide says at least 8″, more in freeze-thaw climates.
How much edging do I need for pavers?
The perimeter, less any side against the house or a wall: 48 ft round a free-standing 12 × 12 ft patio.