Use this guide to plan a patio gravel base at a finished depth of 3 inches, using crushed stone on a compacted base. For a different size, use the Gravel Calculator as the tool for custom sizes.
Recommended patio gravel setup
Choose 3/4-inch crushed stone for a patio: its angular pieces lock together better than rounded stone. Excavate, lay landscape fabric, add the stone in layers, and compact each layer. Keep the finished surface slightly sloped away from the house so water drains off the patio.
How much gravel for a patio at 3 inches deep
Volume in cubic yards = length (ft) × width (ft) × depth (in) ÷ 324. The “order” column adds a 10% allowance for compaction and uneven ground.
| Patio size | Area | Base volume | Order with 10% allowance |
|---|---|---|---|
| 10 × 12 ft | 120 sq ft | 1.11 cubic yards | 1.22 cubic yards |
| 12 × 16 ft | 192 sq ft | 1.78 cubic yards | 1.96 cubic yards |
| 16 × 20 ft | 320 sq ft | 2.96 cubic yards | 3.26 cubic yards |
Worked example: a 14 × 18 ft patio
Area = 14 × 18 = 252 sq ft. Base volume = 252 × 3 ÷ 324 = 2.33 cubic yards. With a 10% allowance: 2.33 × 1.10 = 2.57 cubic yards. Order about 2.57 cubic yards of crushed stone for this patio.
Method note
Measure the finished patio area, not the excavated area, and use the compacted depth of 3 inches in the calculation. If the ground is soft or uneven, the 10% allowance covers most of the difference; add more only if the base will be deeper in places.
Patio gravel questions
Why crushed stone for a patio, rather than pea gravel?
Crushed stone compacts into a firm, stable surface for chairs and tables. Pea gravel stays loose and shifts underfoot, so it suits paths better than a patio seating area.
Do I compact the gravel?
Yes. Compact in thin layers with a plate compactor or hand tamper, and check that the surface stays level and drains away from the house.
Should I use landscape fabric under a patio?
Fabric helps stop the stone sinking into soft soil and limits weeds from below. It does not replace compaction or edging.
What if my patio is not a rectangle?
Split it into rectangles, add their areas, and use the total area with the 3-inch depth. For a custom size, use the Gravel Calculator.
For custom patio sizes, use the Gravel Calculator.