Work out how much paver base you need for a patio, walkway or driveway. Enter the paved area and the compacted base depth and this paver base calculator gives you tons, cubic yards and bags, including the strip of base that runs past the edges. This free online paver base calculator works on any phone or computer, with no sign-up or download.
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Paver base needed
— tons
Quick answer: tons of paver base = (L + 2D) × (W + 2D) × D ÷ 27 × 2.03, with L and W in feet and D the compacted depth in feet. Use 4–6 in for patios and walks and 8–12 in for driveways.
Tons = (L + 2D) × (W + 2D) × D ÷ 27 × 2.03
A 16 × 12 ft patio on 6 in (0.5 ft) of base:
(16 + 1) × (12 + 1) × 0.5 = 110.5 cu ft = 4.09 cu yd. 4.09 × 2.03 = 8.3 tons. With 5% extra: 8.7 tons.
The 2.03 tons per compacted cubic yard is the estimating factor the Tennessee DOT uses for aggregate base. Your supplier’s figure may differ; enter it as a custom density if you buy by the ton.
| Use | Compacted base |
|---|---|
| Walkways and patios | 4–6 in |
| Driveways | 8–12 in |
| Clay or poorly drained soil | Deeper than the above |
Source: Unilock, base preparation. Compact the base in layers of 3–4 in. Unilock’s guidance on base depth gives more for new subdivisions, where the soil hasn’t settled yet.
Bags hold loose material. The bag counts here are an approximation: they assume loose base shrinks to about 1 ÷ 1.4 of its volume when compacted, so a 0.5 cu ft bag gives about 0.36 cu ft of compacted base. The 1.4 is the ratio of two Tennessee DOT estimating factors for road base (2.03 tons per cu yd compacted, 1.45 tons loose). Bagged paver base may compact differently, so check the coverage printed on the bag and buy by that if it differs.
| Patio (base past edges) | Base depth | Compacted cu ft | 0.5 cu ft bags |
|---|---|---|---|
| 10 × 10 ft | 4 in | 37.9 | 107 |
| 16 × 12 ft | 4 in | 70.4 | 198 |
| 16 × 12 ft | 6 in | 110.5 | 310 |
The 1 in bedding layer and the ASTM C33 and C144 sands follow the Interlocking Concrete Pavement Institute’s guide specification, as adapted by the California Concrete Pavement Industry Center.
Also: rectangular prism, bed, trench, room
V = L × W × H
L = length, W = width, H = height or depth.
Example: A 16 × 12 ft patio on 6 in of compacted base that runs 6 in past every edge: 17 × 13 × 0.5 = 110.5 cu ft = 4.09 cu yd × 2.03 = 8.3 tons.
Also: square feet to cubic feet
V = A × d
A = area, d = depth or thickness.
Example: A 200 sq ft walkway on 6 in of base: 200 × 0.5 = 100 cu ft = 3.7 cu yd × 2.03 = 7.5 tons (add the strip past the edges yourself for this shape).
Also: round hole, post hole, tank, planter
V = π × r² × h
r = radius (half the diameter), h = height.
Example: A round patio 12 ft across on 6 in of base: π × 6² × 0.5 = 56.5 cu ft = 2.09 cu yd × 2.03 = 4.3 tons.
A 20 × 12 ft driveway pad on 9 in of base: (20 + 1.5) × (12 + 1.5) × 0.75 = 217.7 cu ft = 8.06 cu yd × 2.03 = 16.4 tons.
Make the base extend past the paver edge by its own depth, so a 16 × 12 ft patio on 6 in of base needs a 17 × 13 ft base. That is 17 × 13 × 0.5 = 110.5 cu ft, or 4.09 compacted cubic yards. At 2.03 tons per compacted cubic yard, that is about 8.3 tons.
Unilock’s guidance is 4–6 in of compacted base for walkways and patios and 8–12 in for driveways, deeper on clay or poorly drained soil. Compact it in layers of 3–4 in, because a plate compactor can’t compact much more than that at once.
As an approximation, a 0.5 cu ft bag holds loose material that compacts to about 0.36 cu ft: about 2.8 bags per compacted cubic foot, or 76 bags per compacted cubic yard. Check the coverage printed on your bag, which may differ. For more than a small walkway, bulk base by the ton is usually far cheaper.
A dense-graded crushed stone that compacts hard, often sold as paver base, crusher run, ¾ in minus or a local DOT base grade. Some installers use clean, open-graded stone for permeable pavers instead. Ask your supplier for the product meant for pavers.
Yes. Standard installations screed a 1 in layer of coarse, concrete-type sand (ASTM C33) over the compacted base and set the pavers on it. Use the paver sand calculator for that layer.
The edge restraint and the outer pavers need support. Unilock’s guidance is to extend the base past the paved edge by a distance equal to the base depth. The calculator adds this automatically for the box shape; you can switch it off.
Yes. The CalcWall Paver Base Calculator is completely free and works online in any browser, on a phone, tablet or computer. There is nothing to download and no account to create, and the math runs right in your browser, so results appear as you type.