Pea Gravel Calculator

Pea gravel calculator: tons for a patio, path, or play area

A pea gravel calculator finds the volume of your area in cubic yards, then multiplies by the weight of a cubic yard. Pea gravel here is 1.4 tons per cubic yard. A 12 × 10 ft patio spread 2 inches deep is 0.74 yd³, which is 1.04 tons, or 1.14 tons with the 10 percent allowance ticked.

Pea gravel is usually a decorative top layer, so the default depth is shallow compared with a gravel driveway.

The formula in plain words

Picture pouring a shallow layer of small round stones across a patch of ground. The thickness is a few inches. The patch has a length and a width. Multiply them to find the pile volume.

• Depth in feet = inches ÷ 12
• Cubic yards = length × width × depth in feet ÷ 27
• Tons = cubic yards × 1.4
• With waste = tons × 1.10 if the box is ticked
• Cost = tons × price per ton

Worked examples

1. Patio, 12 ft × 10 ft, 2 in deep, $60 per ton

• Depth: 2 ÷ 12 = 0.167 ft
• Volume: 12 × 10 × 0.167 = 20 ft³ = 0.74 yd³
• Tons: 0.74 × 1.4 = 1.04 tons, or $62.22
• With waste: 1.14 tons, or $68.44

2. Garden path, 30 ft × 3 ft, 2 in deep

• Volume: 30 × 3 × 0.167 = 15 ft³ = 0.556 yd³
• Tons: 0.556 × 1.4 = 0.78 tons
• With waste: 0.86 tons, about $51.33

Example 2 is under one ton, which is the point where bagged stone becomes a real option. A ton is 2,000 lb, or 40 bags of 50 lb, so the path would take about 31 bags before waste.

Coverage of one ton

One ton at 1.4 t/yd³ is about 19.3 cubic feet.

Depth	Area per ton	Tons per 100 sq ft
1 in	~231 sq ft	0.43
2 in	~116 sq ft	0.86
3 in	~77 sq ft	1.30
4 in	~58 sq ft	1.73

Where pea gravel works, and where it does not

Use	Typical depth	Notes
Garden path	2 in	Edging keeps stones in the path
Patio or seating area	2 to 3 in	Rounded stones are comfortable underfoot
Dog run	2 to 3 in	Drains well and is easy to rinse
Play area	3 to 4 in	Check safety guidance for fall height
Drainage backfill	Fill the trench	Round stones let water move freely
Driveway	Not ideal	Rounded stones roll under tires

The same round shape that feels nice to walk on also means the stones do not lock together. For a driveway, angular stone like crusher run holds better.

How to measure your area

• Include the borders. If a border will also be covered in pea gravel, measure it.
• Curves. Take the longest length and three widths, average the widths, and treat it as a rectangle.
• Check the soil depth. Pull away grass and topsoil first so your depth is below the finished level.
• Round areas. Use the area of a circle, π × radius², for a circular fire pit zone and enter it as length × 1.
• Check for low spots. Water pooling means the base needs regrading before stone goes down.

Common mistakes

• Spreading it straight on soil. Without fabric or a base, stones sink and weeds come up. Use landscape fabric first.
• Making the layer too deep. Over 3 inches, walking feels like walking on a beach.
• Forgetting edging. Without a border, round stones migrate into the lawn and bed.
• Leaving out waste. Settling and uneven ground eat the first inch. The waste box adds 10 percent.
• Ordering from a rough guess. Measure and run the calculator, because a second small delivery can cost as much as the first.

Related calculators

For the base beneath, use the gravel calculator at a 4-inch depth. The gravel path calculator is tuned to narrow walkways, and the river rock calculator handles larger decorative stone.