Pea Gravel Calculator

How the Pea Gravel Calculator Works

This calculator estimates how much pea gravel you need for a path, patio, garden bed or drainage area. Enter the length and width of the area in feet and the depth in inches, and it returns the volume in cubic feet, cubic yards, and the approximate weight in tons.

Pea gravel is sold both by the bag and in bulk by the cubic yard or ton, so having all three figures lets you compare prices and order the right amount.

The Formula

Volume (ft³) = length × width × depth (in feet) Cubic yards = Volume (ft³) ÷ 27 Tons ≈ cubic yards × 1.4

Because depth is usually given in inches, the calculator first converts it to feet by dividing by 12. There are 27 cubic feet in one cubic yard, and dry pea gravel weighs roughly 1.4 tons per cubic yard (about 2,800 lb), which is the standard estimate used for ordering.

Worked Example

For an area 20 ft long and 10 ft wide, covered 2 inches deep:

• Depth in feet = 2 ÷ 12 = 0.167 ft
• Volume = 20 × 10 × 0.167 = 33.3 ft³
• Cubic yards = 33.3 ÷ 27 = 1.23 yd³
• Tons = 1.23 × 1.4 = 1.73 tons

So you would order about 1.25 cubic yards (≈ 1.75 tons) of pea gravel for this project.

Coverage at a Glance

The deeper the layer, the less ground a fixed amount of gravel covers. This table shows roughly how much area one cubic yard spreads at common depths.

Depth	Coverage per cubic yard
1 inch	≈ 324 sq ft
2 inches	≈ 162 sq ft
3 inches	≈ 108 sq ft
4 inches	≈ 81 sq ft

Tips for Ordering Pea Gravel

• Pick the right depth. 2 inches suits decorative cover and ground around plants; pathways and patios want 2–3 inches over a firm base.
• Add a margin. Include 5–10% extra for settling and to refill low spots after the gravel beds in.
• Use edging. Pea gravel rolls easily, so install landscape edging or borders to keep it in place and maintain an even depth.
• Lay a base. A compacted sub-base of crushed stone and a layer of landscape fabric below the pea gravel improves drainage and stops the stones sinking into soil.