How much sand goes under a pool
cu ft = floor area (sq ft) × inches ÷ 12 · cu yd = cu ft ÷ 27 · bags = cu ft ÷ 0.5
A 24 ft round pool covers 3.14 × 12 × 12 = 452 sq ft. A 2 inch base is 452 × 2 ÷ 12 = 75.4 cu ft, which is 2.8 cubic yards, about 3.8 tons at 100 lb per cu ft, or 151 bags of 50 lb. A 15 ft round needs 1.1 cubic yards. Ovals: (length − width) × width + 0.785 × width²; an 18x33 oval covers 524 sq ft. Order a little extra for the cove, the sloped ring of sand that some installers build along the wall.
| Pool | Floor (sq ft) | Cubic yards | Tons (approx.) | 50 lb bags |
|---|---|---|---|---|
| 12 ft round | 113 | 0.7 | 0.9 | 38 |
| 15 ft round | 177 | 1.1 | 1.5 | 59 |
| 18 ft round | 254 | 1.6 | 2.1 | 85 |
| 21 ft round | 346 | 2.1 | 2.9 | 116 |
| 24 ft round | 452 | 2.8 | 3.8 | 151 |
| 27 ft round | 573 | 3.5 | 4.8 | 191 |
| 30 ft round | 707 | 4.4 | 5.9 | 236 |
Which sand, and sand for the filter
Use masonry sand: fine, washed and free of stones, which would push through the liner. Rake it level, wet it and tamp it before the liner goes in. Filter sand is a different product, graded pool filter silica sold in 50 lb bags; the pounds your filter needs are printed on its tank label, so divide by 50 (300 lb is 6 bags). To size the filter itself, use the pool filter size calculator; the water the new pool holds is in the above ground pool volume calculator, and a new liner is priced in the pool liner replacement cost calculator.
Sand depth: Royal Swimming Pools knowledge base, "How much sand do I need for my pool's base?" (2 inch base under the liner, masonry sand) and Hunker, "How deep should the sand be on an aboveground pool" (2 inches standard). Bag yield: Quikrete All-Purpose Sand 50 lb, 0.5 cu ft (Tractor Supply listing). Tons assume 100 lb per cu ft (50 lb per 0.5 cu ft bag); damp sand weighs more. Read October 23, 2026.
Frequently asked questions
How many inches of sand do you need under a pool?
Most above-ground pool guides call for a 2 inch sand base under the liner, raked level and tamped; your pool's manual has the final word. More sand is not better: a thick layer shifts and leaves footprints in the floor. Level the ground itself first, and use the sand only as a smooth cushion.
How much sand do I need for a 24 ft round pool?
At 2 inches: 452 sq ft × 2 ÷ 12 = 75.4 cu ft, which is 2.8 cubic yards, about 3.8 tons, or 151 bags of 50 lb. Bulk sand by the yard is usually cheaper than bags at this size. An 18 ft round needs 1.6 cubic yards and a 15 ft round 1.1.
What kind of sand goes under an above ground pool?
Masonry sand: fine, washed and free of stones and roots, which would wear through the liner. Avoid coarse concrete sand and anything with gravel in it. Play sand works for small pools but costs more per cubic foot. Some owners add foam pads or a ground cloth on top of the sand.
How many bags of sand do I need for my pool filter?
The pounds are printed on the filter tank label and grow with the tank size; pool filter sand comes in 50 lb bags, so divide by 50: 300 lb is 6 bags. Replace the sand every few years, when filtering slows or the water stays cloudy after backwashing.
What size sand filter for a 30,000 gallon pool?
For an 8 hour turnover a 30,000 gallon pool needs 62.5 gpm. At a rated 20 gpm per sq ft, that is 3.1 sq ft of filter area, a 24 inch sand tank. The pool filter size calculator works it out for your gallons and turnover.