Ordering materials is the part of a patio project where a small arithmetic mistake turns into a second delivery fee and a lost weekend.
The math itself is not hard. What trips people up is that the same phrase means two different things, the waste factor changes with the pattern, and base stone is sold by weight while you measured in feet.
This guide covers all of it: what paver sizes actually mean, how to measure any shape, how many pavers you need, how much base stone and sand to order, and how to calculate the slope. Every figure here is worked out so you can check it against your own numbers.
First, Two Different Questions
When people say a 12×12 patio and a 12×12 paver, they mean completely different things, and the search results mix them together constantly.
- A 12 by 12 patio. A patio measuring 12 feet by 12 feet, which is 144 square feet of surface.
- A 12 by 12 paver. A single unit measuring 12 inches by 12 inches, which covers exactly 1 square foot.
The same applies to 16×16 and 24×24, which are almost always paver unit sizes in inches rather than patio dimensions in feet. A 24×24 patio would be 576 square feet, which is a very large patio, while a 24×24 paver is a common large format unit covering 4 square feet.
Both sections are below. Sort out which one you are asking before you start multiplying.
Common Paver Unit Sizes and Coverage
Coverage is what you need for the count. Divide your square footage by the coverage of one unit.
| Paver size | Coverage | Per sq ft | For 100 sq ft | Order with 5% waste |
|---|---|---|---|---|
| 4 x 8 in | 0.22 sq ft | 4.50 | 450 pavers | 473 |
| 6 x 6 in | 0.25 sq ft | 4.00 | 400 pavers | 420 |
| 6 x 9 in | 0.38 sq ft | 2.67 | 267 pavers | 281 |
| 8 x 8 in | 0.44 sq ft | 2.25 | 225 pavers | 237 |
| 12 x 12 in | 1.00 sq ft | 1.00 | 100 pavers | 105 |
| 16 x 16 in | 1.78 sq ft | 0.56 | 57 pavers | 60 |
| 18 x 18 in | 2.25 sq ft | 0.44 | 45 pavers | 47 |
| 12 x 24 in | 2.00 sq ft | 0.50 | 50 pavers | 53 |
| 24 x 24 in | 4.00 sq ft | 0.25 | 25 pavers | 27 |
Coverage is calculated from nominal face dimensions. Actual units are slightly smaller to allow for joint spacing, which the waste allowance absorbs.
Unit sizes are not consistent across materials. Clay brick comes in a narrower range of shapes than concrete, and natural stone is often sold by the pallet in mixed sizes rather than by the piece. Our comparison of how unit sizes differ between materials covers what each product line typically offers.
Common Patio Sizes and What Fits
| Patio size | Square feet | What it holds | Best suited to |
|---|---|---|---|
| 8 x 8 | 64 | Bistro table and two chairs | A landing spot or a very small yard |
| 10 x 10 | 100 | Four person table with chair clearance | The most common small patio |
| 12 x 12 | 144 | Six person table, or a table plus a grill | The most requested size overall |
| 12 x 16 | 192 | Dining plus a small seating area | Two zones without crowding either |
| 16 x 16 | 256 | Dining, lounging and circulation | A comfortable full patio |
| 16 x 20 | 320 | Dining, lounging and a fire feature | Where features start to fit properly |
| 20 x 20 | 400 | Multiple zones with room to move | Entertaining several people at once |
Square patios are the most common request and the least efficient shape for furniture. A rectangle of the same area usually holds more.
If you are working at the small end of this chart, the layout matters more than the square footage. Our look at what the smallest workable footprints look like draws four of them to scale with furniture in place.
How to Measure Your Patio Area
Every calculation downstream depends on one number: the square footage of the finished surface. Get that right and the rest is multiplication.
- Rectangles. Length times width. Measure twice, and check the diagonals match if the shape is meant to be square.
- L shapes. Break the shape into rectangles, calculate each, then add. Do not try to average it.
- Circles. 3.14 times the radius times the radius. A 10 foot diameter circle has a 5 foot radius and covers about 79 square feet.
- Irregular shapes. Draw it on graph paper at one square per foot, count the full squares, and count partial squares as halves. Round up.
- Curves. Treat a curved edge as if it were straight for ordering purposes. You will cut into the extra material anyway.
How Many Pavers Do You Need?
Three steps, and the third is the one people skip.
- Calculate the surface area. Square footage of the finished patio, using the formulas above.
- Divide by the coverage of one paver. From the unit size table. That gives the exact piece count.
- Add the waste factor for your pattern. Cutting produces offcuts you cannot use. This is not optional padding.
| Pattern | Add for waste | Why |
|---|---|---|
| Running bond | 5% | Half cuts at alternating row ends only |
| Stack bond | 5% | Straight cuts along two edges |
| Basketweave | 8% | Pairs have to break at the perimeter |
| Pinwheel | 8% | The repeating unit rarely lands on the edge |
| Herringbone at 90 degrees | 10% | Every course meets the border at an angle |
| Herringbone at 45 degrees | 15% | Diagonal runs into a straight edge everywhere |
| Circle kit into a field | 15% or more | The transition ring produces heavy waste |
Worked Examples
- 12 x 12 in pavers on a 10 x 10 patio. 100 sq ft divided by 1.00 = 100 pavers. Add 5 percent and order 105.
- 16 x 16 in pavers on a 10 x 10 patio. 100 sq ft divided by 1.78 = 57 pavers. Add 5 percent and order 60.
- 16 x 16 in pavers on a 12 x 12 patio. 144 sq ft divided by 1.78 = 81 pavers. Add 5 percent and order 86.
- 24 x 24 in pavers on a 12 x 12 patio. 144 sq ft divided by 4.00 = 36 pavers. Add 5 percent and order 38.
- 4 x 8 in pavers in herringbone on a 12 x 16 patio. 192 sq ft divided by 0.22 = 864 pavers. Add 15 percent and order 994.
One practical note. Pavers are sold by the pallet or by the square foot, not usually by the piece, so round your order up to whatever the supplier sells. Partial pallets carry a premium, and having a few dozen spares in the garage solves future repairs.
How Much Base Stone and Sand to Order
This is where units change on you. You measured in feet, base stone is priced by the ton, and the conversion runs through cubic yards.
- The base formula. Square feet times depth in feet, divided by 27, gives cubic yards. For a 6 inch base, depth is 0.5 feet.
- Converting to tons. Crushed aggregate runs roughly 1.4 tons per cubic yard. Multiply your cubic yards by 1.4.
- Add for compaction. Material compacts as you run the plate over it. Order about 20 percent more than the raw calculation.
- The sand formula. Square feet times 0.083, which is one inch in feet, divided by 27. Use coarse concrete sand.
- Joint sand. About one bag per 50 to 100 square feet, depending on joint width and paver thickness.
- Edge restraint. The perimeter in linear feet, plus one spike per foot of restraint.
| Patio | Sq ft | Base at 6 in | Sand at 1 in | Joint sand | Edge |
|---|---|---|---|---|---|
| 8 x 8 | 64 | 1.2 cy, 1.7 t | 0.20 cy | 1 bag | 32 ft |
| 10 x 10 | 100 | 1.9 cy, 2.6 t | 0.31 cy | 2 bags | 40 ft |
| 12 x 12 | 144 | 2.7 cy, 3.7 t | 0.44 cy | 2 bags | 48 ft |
| 12 x 16 | 192 | 3.6 cy, 5.0 t | 0.59 cy | 3 bags | 56 ft |
| 16 x 16 | 256 | 4.7 cy, 6.6 t | 0.79 cy | 4 bags | 64 ft |
| 20 x 20 | 400 | 7.4 cy, 10.4 t | 1.23 cy | 5 bags | 80 ft |
Tonnage assumes 1.4 tons per cubic yard for dense graded aggregate. Add roughly 20 percent to the base figure for compaction, and confirm the conversion with your supplier.
Once the order list is set, the sequence of the build determines when each material has to be on site. Our step by step on putting the measurements into practice covers what gets delivered when.
Paver Patio Slope: How to Calculate the Fall
A patio has to shed water away from the house. The standard is a quarter inch of drop for every foot of run, which works out to about a 2 percent grade.
The formula is simply the run in feet multiplied by 0.25 inches. A 16 foot patio needs 4 inches of total fall from the house edge to the far edge. A 12 foot patio needs 3 inches.
- Set a stake at the house edge at finished height. This is your high point and it does not move.
- Run a string to a stake at the far edge and level it. Use a line level or a laser. Get it truly level first.
- Drop the far end by the calculated amount. Mark the string down by the total fall figure. That is your finished surface line.
- Excavate parallel to that line. Dig your full depth measured down from the sloped string, not from level ground.
- Hold the slope through every layer. Base, bedding sand and pavers all follow the same fall. You cannot create slope in the sand.
Where the patio wraps a corner or the yard falls sideways, slope it toward the lowest usable point rather than forcing it away from the house in every direction. What matters is that water leaves the surface and does not run toward a foundation or into a neighbor’s yard.
Getting dimensions and clearances right on the drawing is the same discipline whether the surface is at grade or raised. See how dimensions and spacing work on a raised surface for the equivalent numbers on a built structure.
Digital Calculators and Planning Tools
- Manufacturer calculators. Most major paver brands offer one on their site. They are accurate for their own products because the coverage figures come from the actual units.
- Supplier calculators. Landscape supply yards often have a tonnage calculator for base stone. Useful because they know the density of what they are actually selling you.
- Graph paper. One square per foot. Still the fastest way to test whether a table and chairs fit before you commit.
- A rope and spray paint. The most accurate planning tool available, because it accounts for the slope, the tree roots and the gate you forgot about.
Whatever tool you use, take the final number to your supplier and have them check it. They calculate these every day and they will catch an error in the units before it becomes a delivery.
Measuring Mistakes That Cause Reorders
- Measuring the excavation instead of the surface. The dig runs 6 to 8 inches wider than the patio on every side. Order pavers for the finished surface, base stone for the excavation.
- Forgetting the waste factor. Ordering exactly 100 square feet for a 100 square foot patio guarantees a second trip.
- Mixing inches and feet. The single most common arithmetic error here. Convert everything to feet before dividing by 27.
- Using nominal instead of actual dimensions. A 12 inch paver is usually slightly under 12 inches so the joints work out. The waste allowance covers this.
- Skipping the compaction allowance on base stone. Aggregate loses volume as it compacts. Coming up short mid lift stops the job.
- Not accounting for the border course. A soldier course around the perimeter uses different units than the field and gets counted separately.
- Measuring only one direction on an old patio. Existing surfaces are rarely square. Measure both ends and both sides.
Once you have a final square footage, it converts directly into a budget range. Our breakdown of turning square footage into a budget gives the per square foot figures to multiply against.
Frequently Asked Questions
How many 12×12 pavers do I need for a 10×10 patio?
One hundred, since a 12 by 12 inch paver covers exactly one square foot and a 10 by 10 patio is 100 square feet. Order about 105 to cover cutting waste.
How many 16×16 pavers for a 10×10 patio?
Fifty seven. A 16 by 16 inch paver covers 1.78 square feet, so 100 divided by 1.78 is 56.25, rounded up. Order 60 with waste included.
How many 16×16 pavers for a 12×12 patio?
Eighty one for the exact area of 144 square feet. Order 86 to allow for cutting.
How do I calculate how much base gravel I need?
Multiply square feet by the base depth in feet, then divide by 27 for cubic yards. Multiply by about 1.4 for tons, then add roughly 20 percent for compaction.
What slope should a paver patio have?
A quarter inch of fall per foot of run, always away from the house. That is 3 inches across a 12 foot patio and 4 inches across a 16 foot patio.
How much sand do I need under pavers?
One inch of coarse concrete sand, which works out to square feet times 0.083 divided by 27 for cubic yards. A 144 square foot patio needs about 0.44 cubic yards.
What is the most common patio paver size?
The 4 by 8 inch rectangle remains the most widely used unit, though 12 by 12 and larger format units in the 16 to 24 inch range have grown quickly for modern designs.
Should I order extra pavers?
Yes. Five percent for a simple pattern and up to 15 percent for herringbone at 45 degrees. Keep the leftovers dry, because matching a discontinued color years later is often impossible.
The Bottom Line
Everything on this page comes down to three numbers: the square footage of the surface, the coverage of one paver, and the waste percentage for your pattern. Multiply and divide those correctly and the order list writes itself.
The practical next step is to measure the space twice, sketch it on graph paper at one square per foot, and run the numbers before you visit a supplier. Walk in with square footage, a paver size and a pattern, and any yard can price the whole job in a few minutes.
And build the slope into your measurements from the start. It is the one figure that cannot be corrected later without taking the patio apart.