How much sand do you need for a 3×3 sandbox?
A 3×3 ft sandbox filled 6 inches deep takes 4.5 cubic feet of sand — 9 bags of 50 lb play sand. For 12 inches deep, buy 18 bags.
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Your results
Sand needed9 bags (50 lb)
Cubic feet4.5 cu ft
Cubic yards0.17 cu yd
Tons (bulk)0.23 tons
Sand for a 3×3 sandbox by depth
| Depth | Cubic feet | 50 lb bags | Tons (bulk) |
|---|
| 4 in | 3 | 6 | 0.15 |
| 6 in | 4.5 | 9 | 0.23 |
| 8 in | 6 | 12 | 0.3 |
| 10 in | 7.5 | 15 | 0.38 |
| 12 in | 9 | 18 | 0.45 |
Bags are the practical choice at this size; look for sand labeled as washed play sand. A breathable cover keeps out leaves and animals.
The math
3 × 3 × 6 in ÷ 12 = 4.5 cu ft
4.5 ÷ 0.5 cu ft per bag = 9 bags
Common questions
How many bags of sand for a 3x3 sandbox?
9 bags of 50 lb sand at 6 inches deep, or 18 bags at 12 inches.
Want the full method, tips and other sizes? See the sand calculator guide.
Last reviewed November 1, 2026. Results are estimates — confirm with your supplier.
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