How to Use This Calculator
Enter your patio length and width in feet. Set the depth in inches based on how you are building: 4 inches for a single-layer decorative gravel patio, or 5 to 6 inches if you are using a compacted crushed stone base layer under the surface gravel.
Select Pea Gravel or River Rock from the type menu. Pea gravel is the most common patio surface material; river rock works better as a border. The type selection changes the ton estimate, since gravel density varies by material.
The result shows cubic yards for your bulk delivery order, tons for quarry pricing, and a cost range based on current bulk gravel prices. A 10% settling allowance is built in. For L-shaped patios or irregular areas, run the calculator twice and add the cubic yard totals.
How to Calculate Gravel for a Patio
The formula is the same for any gravel project: cubic yards = (length × width × depth ÷ 12) ÷ 27. Convert depth from inches to feet first by dividing by 12. Multiply all three dimensions to get cubic feet. Divide by 27 because there are 27 cubic feet in one cubic yard.
Example: 12 × 16 patio at 4 inches deep. Depth in feet: 4 ÷ 12 = 0.333 ft. Volume: 12 × 16 × 0.333 = 64 cubic feet. Cubic yards: 64 ÷ 27 = 2.37 yards. Add 10% for settling: 2.37 × 1.10 = 2.61 cubic yards. Order 3 cubic yards. In tons (pea gravel at 1.35 t/yd): 2.61 × 1.35 = 3.52 tons.
For a 10 × 10 patio at 3 inches deep: 10 × 10 × 0.25 = 25 cubic feet ÷ 27 = 0.93 cubic yards, plus 10% = 1.02 cubic yards. One cubic yard is the minimum delivery at most bulk landscape suppliers. Even for a small patio, a bulk delivery beats buying individual bags.
Gravel Patio Tips
Install edging before the gravel goes down, not after. Mark your patio outline with spray paint or string lines, dig a shallow trench around the perimeter, and stake the edging in place. Steel landscape edging stays straight for decades. Plastic edging is easier to bend around curves. Either works; what does not work is adding gravel first and trying to tuck edging in afterward.
Build a two-layer base for a patio that holds up to furniture and daily use. Start with 3 to 4 inches of compacted 3/4-inch crushed stone as the base. Compact with a plate compactor or hand tamper. Then add 1 to 2 inches of pea gravel on top as the finished surface. The crushed stone base handles load and prevents sinking; the pea gravel provides the comfortable, attractive surface layer.
Pea gravel shifts underfoot. If your patio will have dining chairs or other furniture that requires a stable surface, consider 3/8-inch crushed angular stone as the top layer instead of round pea gravel. Angular stone compacts slightly and stays put better under chairs and tables. You can still achieve a clean, natural look; the material is just a bit finer and more angular than traditional pea gravel.
What to Buy
For the surface layer: pea gravel in 3/8-inch size. Natural colors (tan, brown, gray mixed) are widely available from landscape suppliers and quarries. Order in bulk for any patio over 6 × 6 feet. A 50-pound bag covers about 0.5 cubic feet; at that rate, bags cost three to four times more per cubic yard than a bulk delivery. Call at least two local suppliers for delivered pricing.
For the base layer: 3/4-inch crushed stone or road base. It compacts well and provides a stable, level foundation. You will also need non-woven landscape fabric (sold by the roll at Home Depot or Lowe's) and steel or plastic landscape edging. Buy the edging first, confirm your patio perimeter, then order gravel. Most landscape suppliers can deliver both the base stone and decorative pea gravel in a single order.