How Much Sand for a 20x18 Patio?
A 20 by 18 foot patio is 360 square feet. How much sand for a 20x18 patio depends on depth: at 3 inches it is about 3.33 cubic yards or 4.5 tons. Suppliers usually sell by the ton, so the tonnage is the number to give them.
Volume and tonnage calculator →The math for a 20x18 patio
- Area: 20 × 18 = 360 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic feet: 360 × 0.250 = 90.0 cu ft.
- Cubic yards: ÷ 27 = 3.33 yd³.
- Tons: × 1.35 = 4.5 tons.
The volume and tonnage calculator does this for any size.
Sand needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 1 in | 1.11 | 1.5 | 1.7 |
| 2 in | 2.22 | 3.0 | 3.3 |
| 3 in | 3.33 | 4.5 | 5.0 |
| 4 in | 4.44 | 6.0 | 6.6 |
About sand
Sand weight changes a lot with moisture. Damp sand can weigh noticeably more per yard than dry sand, so a ton of wet sand covers less area than the same ton dry. Weight per yard is a planning number; the scale ticket at the yard is the real one.
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. Since the patio carries foot traffic and furniture, a little extra depth is cheap insurance.
Ordering tips
- Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
- Delivery size. 5.0 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.
When to choose sand
Works well for:
- Paver and flagstone bedding
- Leveling under above-ground pools (with the right product)
- Filling joints and backfilling pipe
Poor fit for:
- Driveway bases, since sand shifts under load
- Steep areas exposed to runoff
- Thick layers under pavers, which settle unevenly
Quick reference numbers
- Per inch over 100 sq ft: about 0.42 tons of sand (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.2 tons.
- Another size for comparison: a 20x25 area at 2 inches takes about 4.2 tons.
- Weight used here: about 1.35 tons per cubic yard.
Mistakes that throw off the order
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
- Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.
Questions people ask
How many tons of sand for a 20x18 patio?
About 4.5 tons at 3 inches deep, or 5.0 tons with 10 percent extra.
How many cubic yards is a 20x18 patio at 3 inches?
About 3.33 cubic yards.
How much does a cubic yard of sand weigh?
Usually around 1.3 to 1.5 dry tons, depending on stone size, fines and moisture.
How deep should sand be for a patio?
The table above shows 1 to 4 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.
How many square feet is 20x18?
360 square feet.
Related guides
- How Much Does a Ton of Sand Cover?
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Does a Ton of Gravel Cover? Depth Chart
- How Much Sand for a 20x14 Patio?
- How Much Sand for a 20x16 Patio?
As an Amazon Associate, AsphaltTons.com earns from qualifying purchases. Product links below are sponsored.