Paver Base Calculator: Stone and Dig Depth for an Ohio Patio
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Stand at the back door and look at the grass you intend to pave. What you can see is the finished patio. What decides whether it is still flat in five winters is the layer nobody sees, and the paver base calculator sizes it. On the silty clay loam across northeast and central Ohio, with a dense subsoil underneath that holds water where it falls, that layer has to be thicker than a general how-to will tell you. This page follows one patio from marking out to rolling.
The example throughout is a 13 by 24 ft patio against the back of the house, with invented dimensions.
Marking It Out on the Grass, Plus Six Inches All Round
Spray or stake the paved outline first, then push the base out 6 inches past every open edge. That extension is not waste. Edge restraint has to be spiked into compacted stone rather than lawn soil, and without it the outside course of pavers walks outward a little every freeze.
Our patio touches the house along one 24 ft side. Extending 6 inches at both ends of that run gives 25 ft, and 6 inches on the single open long edge gives 13.5 ft. The base footprint is 25 x 13.5 = 337.5 sq ft. The paved area is only 312, so the extension added 8 percent before any depth was chosen.
Reading the Subgrade Before Picking a Depth
Dig a test hole a spade deep at the low corner and look at what comes out. Gray mottling, a sticky ribbon that rolls between your fingers, or a hole that holds water overnight all say clay, and clay is the normal answer in Ohio.
Compacted base depths for this site's ground:
| What goes on top | Compacted base depth |
|---|---|
| Garden path or walkway | 4 inches |
| Patio or seating area | 4 to 6 inches |
| Drive that carries cars | 6 to 8 inches |
| Clay or soft subgrade | add 2 inches, and put woven geotextile underneath |
Our patio is a seating area on clay, so it takes 6 inches, with fabric under the stone to stop the base being pushed down into wet subgrade through the spring. Frost in this state reaches roughly 32 inches, and 36 inches or more across the north, with the figure set by each local building department. No patio base reaches that. What the extra depth buys is a layer that drains and spreads load rather than one that traps water and lifts.
Running the Paver Base Calculator at the Rolled Depth
Enter the base footprint, not the paved outline, and enter the finished rolled thickness, not the loose heap.
The form takes a rectangle, a circle, or up to five areas added together for a patio that steps around a corner. Length and width in feet, diameter in feet, depth in inches from 0.25 to 24. Choose the material so the weight is right, leave the box that adds 10 percent for compaction and spillage ticked, and calculate. Cubic yards, tons and cubic feet come back together, and the results panel will email them.
For the example: 337.5 sq ft x (6 ÷ 12) = 168.75 cubic feet. That is 168.75 ÷ 27 = 6.25 cubic yards, and at 1.50 tons per cubic yard, 9.38 tons. With the 10 percent box it reads 10.32. Order 10.5.
Digging to the Whole Stack, Not to the Base
The hole is deeper than the stone. Add the layers: 6 inches of base, 1 inch of bedding sand, and a paver 2 3/8 inches thick makes 9 3/8 inches. If the patio is to finish half an inch above the lawn so water sheds off it, dig 8 7/8 inches below the existing grass line.
Mark that figure on a stake and check against it as you dig, because over-digging costs twice. You pay to move the spoil and then you pay in stone to bring the level back up. Run the same 337.5 sq ft footprint at 8.875 inches through the dirt calculator and it shows 9.2 cubic yards of soil coming out, which is more than most people plan somewhere to put.
Pitch the bottom of the hole 2 to 3 percent away from the house while you are down there. The base follows the subgrade, the sand follows the base, and the pavers follow the sand, so the fall is set here or not at all.
Spreading in Two-Inch Lifts and Rolling Each One
Six inches goes in as three 2 inch lifts, each one misted lightly and passed over with a plate compactor until it stops moving under the plate. Damp material keys together; bone-dry material just rearranges itself.
Do not try to make up base depth with a deeper sand bed. Sand shifts under load, and a patio bedded on 2 inches of it will be rocking by the second spring. Depth belongs in the stone.
If you are rebuilding over an existing patio, lift the pavers, rake off the old bedding sand and test what is left. A base that is still level, firm and draining takes a fresh 1 inch bedding layer and little else. Soft spots, standing water or low areas mean the base comes out too, because leaving them puts the same dip back under the new pavers.
Where the 1.50 Comes From, and Why the Sand Is Calculated Apart
The volume arithmetic is fixed: length times width times depth in inches divided by 12 gives cubic feet, and 27 cubic feet make a cubic yard. The tonnage depends on what fills it. A crushed course carrying its own fines, 411 limestone or 304 Aggregate Base, weighs about 3,000 lb per cubic yard, which is the 1.50 above. One ton of it covers about 54 sq ft at 4 inches, 43 at 5, 36 at 6 and 27 at 8.
Screenings weigh 1.45 and are a leveling course, not a structural one; used deep they hold water and creep. Mason Sand weighs 1.35, and the bedding inch is sized on the paver sand calculator over the same 337.5 sq ft, which works out at 1.04 cubic yards or 1.4 tons. The same 411 limestone under a lane or a shed pad instead of a patio is sized on the crusher run calculator, where the depths run deeper. Three tools, one delivery, and Ohio Rock Supply will bring the materials together by ZIP at checkout. Have the drop made after the hole is dug, since a heap of stone parked on the lawn for two weeks kills a rectangle of grass you then have to fix.
Common questions
The patio wraps around the corner of the house in an L. How do I enter it?
Split it at the inside corner into two rectangles and use the multiple-areas option, up to five at a time. Measure each leg with its own 6 inch extension on its open edges only, and count the corner square in one leg rather than both. Keep the depth the same across both so the compactor sees one continuous base.
Does the 6 inch extension really need to be in the order?
Yes, and on a small patio it is a real fraction of it. On the 13 by 24 example the extension turns 312 sq ft of paving into 337.5 sq ft of base, which is about three quarters of a ton at 6 inches. That strip is what the edge restraint spikes into, so leaving it out means either a short order or an unsupported outside course.
How do I split the order between the base and the sand on top of it?
Run the footprint twice. Once at the compacted base depth on stone at 1.50 tons per cubic yard, and once at exactly 1 inch on sand at 1.35. They are different materials at different weights, so a single run at 7 inches would give a figure that is wrong for both. Order each product for its own tonnage.
One side of the patio is a curve. What goes in the box?
Box the curve into the smallest rectangle that contains it and take the over-estimate, which on a base you will use up in the extension anyway. If the curve is a proper arc, enter the rectangle for the straight part and a circle for the rounded end as a second area, then halve the circle figure by hand if only half of it is paved.
The old patio only sags in one corner. Can I calculate just that patch?
Yes. Lift the pavers over the soft area, measure the patch you are taking back to subgrade, and run that rectangle alone at the full base depth. Add a few square feet around it, because the repair has to key into sound base rather than butt against it, and expect to re-bed a wider area than you dug so the surface reads level across the joint.
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.