Paver Base Calculator for Patios, Paths and Paver Drives
Enter your project dimensions
Patio season here is set by the subgrade rather than by the calendar. Work runs close to year round in this state, but a base is only as good as the compaction under it, and cherty clay that has taken rain since December will not compact in March, it will just move. The dependable stretch is late summer into fall, when the ground has dried enough to take a roller. Measure now, order against a dry week, and start with the part of the measurement most people miss.
Running a tape around a patio that ends in a curve
Measure the paved area first, as the pavers will actually sit. Anything that is not a rectangle gets broken into pieces: an L is two rectangles, a rounded corner is a rectangle plus a quarter circle, a seating bump-out is its own small rectangle. The tool totals up to five areas in one estimate, with length and width in feet or a diameter for a circle.
Be generous with curves. A base under a curved edge has to run past the arc rather than stop at it, so measure to the widest point and treat the paved shape as the rectangle that contains it.
Why the stone footprint is bigger than the patio you are paving
This is the step that turns a correct measurement into a short order. The base has to extend about six inches past every open edge of the paving, because the edge restraint sits on compacted stone rather than on lawn soil. Take that away and the outer course walks outward over a couple of wet winters and the joints open behind it.
So the footprint you enter is bigger than the patio. A 21 by 15 foot patio against the back of a house has three open edges: the two 15-foot sides and the far 21-foot side. Add half a foot to each. The width becomes 15.5 and the length becomes 22, so the base footprint is 15.5 x 22 = 341 square feet against 315 square feet of paving. That is eight percent more stone, found with a tape rather than after the load arrives.
A free-standing patio or a path open on all four sides gets the half foot on every side.
Entering the rolled depth, not the depth you tip
Put the base footprint in as length and width in feet, and the compacted depth in as inches. The depth field accepts 0.25 through 24. Choose the material, and leave ticked the box that adds ten percent for compaction and spillage, which on a base course is worth having on.
The depth you type is the finished depth after rolling, not the loose stone you spread. Build the base in two-inch lifts, mist each one, and compact it before the next goes down. Damp stone packs; dry stone rolls around under the plate.
Two things to build in as you go. Pitch the compacted base two to three percent away from the house, because whatever contour is in the base comes through the sand and the pavers unchanged. And on clay, put woven geotextile under the stone so the base does not press into a subgrade that softens every spring.
Four inches under chairs, six on Basin clay, eight where it stays soft
| Where it is going | Compacted base | 1 ton covers |
|---|---|---|
| Garden path or walkway | 4 in | about 54 sq ft |
| Patio or seating area on firm ground | 4 to 6 in | 54 to 36 sq ft |
| Anything cars park or turn on | 6 to 8 in | 36 to 27 sq ft |
| Clay or soft subgrade | add 2 in and fabric |
Thin clay over limestone across the Central Basin, and the cherty clay of the Highland Rim, both belong in the six-inch row rather than the four. On the plateau and the eastern ridges the rock is often close under the surface, which gives a firmer subgrade, but the runoff arrives fast and concentrated, so the fall you build into the base matters as much there as the depth.
Two inches of stone is not a base. It is a leveling course, and a patio built on it will rock inside a season.
Tons of stone in, cubic yards of clay out
Crusher run is the material for this layer and it runs about 3,000 lb a cubic yard on this site's published figures, which is 1.50 tons. Cubic feet divided by 27 gives cubic yards; cubic yards times 1.50 gives tons.
The other number worth having before you start is the spoil. Excavation depth is the base, plus one inch of bedding, plus the paver thickness, less however much you want the finished surface standing above the lawn. A six-inch base under a standard 2 3/8 inch paver with a half inch reveal digs to 6 + 1 + 2.375 - 0.5, which is 8.875 inches, call it 9. Over 341 square feet that is 341 x 8.875 ÷ 12 = 252.2 cubic feet, or 9.3 cubic yards of clay to put somewhere. Run it through the dirt calculator if you would rather see it as tons.
Mark that dig depth on a stake and check it as you go. Over-digging costs twice, once to move the soil out and once to buy stone to bring the grade back.
Working a 21 by 15 seating area through, on Basin clay
A hypothetical one, on Basin clay, so six inches of base. The footprint from earlier is 341 square feet. 341 x 6 ÷ 12 = 170.5 cubic feet. 170.5 ÷ 27 = 6.31 cubic yards. 6.31 x 1.50 = 9.47 tons, which reads 10.42 with the ten percent ticked. Order 10.5 tons of crusher run, and size the inch of bedding underneath the pavers separately on the paver sand calculator, because that is a different material at a different weight.
Have the stone dropped after the hole is dug. A pile standing on the lawn for two weeks leaves a dead rectangle you will be reseeding in the fall.
A 32-foot path, and an old patio worth keeping the base of
A path 32 feet long and 4 feet wide, open on all sides, takes the half foot all round: 33 by 5, so 165 square feet. At 4 inches, 165 x 4 ÷ 12 = 55 cubic feet, which is 2.04 cubic yards and 3.06 tons, or 3.37 with the extra. Three and a half tons covers it.
A patio being re-laid is the smaller job. Lift the pavers, sweep off the old bedding, and look at what is underneath. A base that is firm underfoot, level and not holding water after a storm can stay, and you need a fresh inch of bedding and a fraction of the stone a new build would take. Soft ground, low spots or standing water means the base comes out too, since leaving a failed one under new pavers buys the same failure again.
Screenings belong in this job only as a thin leveling skim over a compacted base, never as the base itself. And if there are no pavers involved at all, a plain gravel pad or lane is a simpler calculation without the overhang or the dig stack: use the crusher run calculator for that. When the tonnage is settled, pick a quantity and a date on the product page, and check the tip spot and access before you book.
Common questions
Is the depth I enter the loose stone or the finished layer?
The finished, compacted layer. Every depth on this page is written that way, and so are the figures an inspector would work from. Spread it in two-inch lifts and compact each one, and expect the loose material to lose something like a tenth of its height under the plate. If you enter loose depth you will finish shallow, which on a patio shows up as a dip a year later.
My patio is a half circle off a deck. What do I put in the diameter field?
The full diameter of the circle it is cut from, then halve the result. A semicircle 12 feet across the straight edge comes from a 12-foot circle: 0.7854 x 144 = 113 square feet, so the paving is 57. Add the overhang by working from a 13-foot circle instead, which gives 133 square feet, halved to 66. Round up rather than down on a curve.
How do I check the tonnage by hand?
Base footprint in square feet, times compacted depth in inches, divided by 12, divided by 27, times 1.5. A 10 by 12 patio open on three sides gives a base footprint of 11 by 12.5, which is 137.5 square feet. At 4 inches: 137.5 x 4 ÷ 12 = 45.8 cubic feet, ÷ 27 = 1.70 yards, x 1.5 = 2.55 tons.
Why does the same patio need different tonnage if I change the material?
The volume stays the same and the weight per yard does not. On this site's figures crusher run is about 3,000 lb a cubic yard, screenings about 2,900, and coarse bedding sand about 2,700. Three materials, three answers for the same hole, which is why the material select changes the result and why the base and the bedding are ordered separately.
Is ten percent enough of a margin on a base order?
For a firm, well-drained subgrade, yes. It covers spillage and the stone that ends up outside the edge of the run. It does not cover a soft subgrade, where the first lift partly disappears into the ground before it starts building anything. On clay that was still wet when you dug it, add the two inches of depth from the table rather than leaning on the tick box.
Related calculators
The pavers get the compliments. The base earns them.
Crusher run and screenings by the ton, free delivery, ordered together with your bedding sand.