Pea Gravel Calculator
One ton of pea gravel covers approximately 100 square feet at 2 inches deep or 50 square feet at 4 inches deep. A standard 3 ft wide by 20 ft long garden path at 2-inch depth needs about 0.37 cubic yards — roughly half a ton.
Worked example: A 10 by 12 ft patio at 3-inch depth: (10 x 12 x 0.25) / 27 = 1.11 cubic yards = approximately 1.5 tons of pea gravel.
Use cases: decorative paths, patios, drainage layers for French drains, and playground surfacing are the four most common applications.
Compaction note: pea gravel does not compact due to its smooth rounded shape. Use a 2- to 4-inch crushed stone base underneath for any patio or path that will see foot traffic. Without a base, pea gravel shifts underfoot and migrates to the edges over time.
Drainage: pea gravel has excellent drainage properties — water passes through quickly, making it ideal for rain gardens and French drain trenches where fast percolation is the goal.
Playground safety: the Consumer Product Safety Commission recommends 9 to 12 inches of pea gravel under playground equipment for fall protection at heights up to 7 feet. Loose-fill surfacing must be maintained at the proper depth — it compacts over time in high-traffic zones under swings and at slide exits.
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Frequently Asked Questions
Does pea gravel compact?
Pea gravel does not compact well due to its rounded shape. Use crushed stone under it as a base layer.
How much pea gravel for a path?
A standard garden path 3 ft wide by 20 ft long at 2 inches deep needs about 0.37 cubic yards or roughly 0.5 tons of pea gravel.
What depth of pea gravel for a patio?
Use 3 to 4 inches of pea gravel for a patio. Set a 1-inch layer of sand underneath for stability, as pea gravel does not compact on its own.
What depth of pea gravel do I need for drainage?
For a French drain or rain garden, use 4 to 6 inches of pea gravel over a perforated pipe. The gravel acts as a void space for water to pass through. A 12-inch wide by 6-inch deep trench holds about 0.022 cubic yards per linear foot.
How much pea gravel for a 100 square foot path at 2 inches deep?
A 100 sq ft path at 2 inches deep needs 0.62 cubic yards or roughly 0.85 tons (about 1,700 lbs) of pea gravel. At 4 inches deep, double that to 1.24 cubic yards or 1.7 tons.