Pea Gravel Calculator: How Much Pea Gravel Do I Need?
Enter your area dimensions to get cubic yards, tons, and 50 lb bag count for pea gravel (3/8″, 1.35 ton/yd³). Includes a retail-vs-bulk cost comparison.
Pea gravel is the most popular decorative stone for garden paths, fire-pit surrounds, and drainage channels. Its smooth 3/8″ stones shed water, resist compaction, and look great in beds. Because it does not interlock, it needs landscape fabric underneath and edging along the borders to stay in place.
This calculator pre-selects pea gravel density (1.35 ton/yd³). Adjust length, width, depth, and waste allowance below, then see tons, cubic yards, bags, and a bulk-vs-bagged cost breakdown instantly.
Project Dimensions
How the math works
Step 1 — volume in cubic yards
cu yd = (length_ft × width_ft × depth_in) ÷ 324 324 = 27 cu ft/yd × 12 in/ft. A canonical landscaping shortcut: multiply area by depth (in inches) and divide by 324.
Step 2 — apply waste / compaction allowance
cu yd (with waste) = cu yd × (1 + waste % ÷ 100) The waste allowance inflates both tonnage and bag count — you buy the waste-inclusive amount.
Step 3 — tons
tons = cu yd × density (ton/yd³) Material densities (US short tons per cubic yard): pea gravel 1.35, #57 stone 1.40, paver base 1.40, river rock 1.30, crusher run 1.40. Confirm exact weight with your supplier — density varies with moisture and stone source.
Step 4 — retail bags
bags = ⌈ cu yd × 54 ⌉ A standard 50 lb bag holds 0.5 cu ft. One cubic yard = 27 cu ft ÷ 0.5 = 54 bags.
How pea gravel differs from other materials
Unlike crusher run or paver base, pea gravel is an open-graded stone — the round particles leave air voids and do not compact under foot traffic. That makes it excellent for drainage but unsuitable as a structural base. For a driveway sub-base or patio foundation, use crusher run or paver base instead.
At 1.35 ton/yd³, pea gravel is slightly lighter than compacted bases (1.40 ton/yd³) and slightly heavier than river rock (1.30 ton/yd³). The 10% waste default is appropriate for decorative work; you can lower it to 5% for small, tidy beds with good edging.
Frequently Asked Questions
Dry pea gravel (3/8") weighs approximately 2,700 lb per cubic yard, or 1.35 US short tons. Wet pea gravel can weigh 10–15% more — confirm exact weight with your supplier before ordering.
A 50 lb bag holds about 0.5 cu ft. One cubic yard = 27 cu ft ÷ 0.5 = 54 bags. For most pea gravel projects over half a cubic yard, bulk delivery beats bagged on price by a wide margin.
For a decorative garden path, 2–3 in of pea gravel is typical. For a patio or fire-pit surround, 2–4 in works well. Pea gravel does not compact — you need landscape fabric underneath to prevent sinking and weed growth.
Yes. Pea gravel is round and will not lock together; without landscape fabric the gravel sinks into the soil and weeds push through. Lay a heavy-duty geotextile fabric before spreading the stone.
Tons = (length ft × width ft × depth in) ÷ 324 × 1.35. The divisor 324 converts area×depth from square-foot·inches to cubic yards; then 1.35 ton/yd³ is the pea gravel density. Add 10% for waste/spillage.