How Much Pea Gravel for a 16x20 Patio?
How much pea gravel for a 16x20 patio: at 3 inches deep you need about 2.96 cubic yards, which is roughly 4.1 tons at 1.4 tons per yard. The patio covers 320 square feet, so every inch of depth adds about 0.99 yards.
Volume and tonnage calculator →The math for a 16x20 patio
- Area: 16 × 20 = 320 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic feet: 320 × 0.250 = 80.0 cu ft.
- Cubic yards: ÷ 27 = 2.96 yd³.
- Tons: × 1.4 = 4.1 tons.
The volume and tonnage calculator does this for any size.
Pea gravel needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 2 in | 1.98 | 2.8 | 3.0 |
| 3 in | 2.96 | 4.1 | 4.6 |
| 4 in | 3.95 | 5.5 | 6.1 |
About pea gravel
Because pea gravel is round, it never fully locks. Keep depths modest on walkways and patios so it does not feel like walking on a beach, and use edging. Ask your supplier for their own tons-per-yard figure, since stone source and moisture shift it.
Preparing the patio
Remove sod, level the area with a slight slope away from the house, and lay landscape fabric if weeds are a concern. Edging keeps loose material inside the patio footprint. For foot traffic and furniture, the depths in the table above are a reasonable starting range.
Ordering tips
- Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
- Delivery size. 4.6 tons fits in a single typical dump truck load; small loads may carry a delivery fee. See how many tons of gravel in a dump truck.
- Bulk vs bags. At this size bulk delivery is usually the practical choice.
- Where it drops. Have the truck dump as close to the patio as firm ground allows.
Good and poor uses for pea gravel
Good uses:
- Patios, walkways and dog runs
- Play areas with proper depth and edging
- Drainage around foundations when sized properly
Poor fit for:
- Driveways and steep paths, where it rolls and ruts
- Under pavers as a base
- Areas without edging
Quick reference numbers
- Per inch over 100 sq ft: about 0.43 tons of pea gravel (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.3 tons.
- Another size for comparison: a 15x30 area at 4 inches takes about 7.8 tons.
- Weight used here: about 1.4 tons per cubic yard.
Mistakes that throw off the order
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
- Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.
- Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
Questions people ask
How many tons of pea gravel for a 16x20 patio?
About 4.1 tons at 3 inches deep, or 4.6 tons with 10 percent extra.
How many cubic yards is a 16x20 patio at 3 inches?
About 2.96 cubic yards.
How much does a cubic yard of pea gravel weigh?
Usually around 1.3 to 1.5 tons, depending on stone size, fines and moisture.
How deep should pea gravel be for a patio?
The table above shows 2 to 4 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.
How many square feet is 16x20?
320 square feet.
Related guides
- How Much Does a Ton of Gravel Cover? Depth Chart
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Pea Gravel for a 16x16 Patio?
- How Much Pea Gravel for a 16x18 Patio?
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