How much sand for a 4×4 sandbox?
Quick Answer
A 4×4 foot sandbox filled 6 inches deep needs 8 cubic feet of sand, which is approximately 8 bags of 50-lb play sand (each covers ~1 cu ft) or 4–5 large bags of 100-lb play sand. At a shallower 4-inch depth, you need about 5 cubic feet.
Quick Reference Table
| Fill depth | Sand for 4×4 sandbox |
|---|---|
| 3 inches | 4 cu ft ≈ 4 bags (50-lb) |
| 4 inches | 5.3 cu ft ≈ 6 bags (50-lb) |
| 6 inches | 8 cu ft ≈ 8 bags (50-lb) |
| 8 inches | 10.7 cu ft ≈ 11 bags (50-lb) |
How to Calculate It Yourself
- 1
Calculate sandbox volume: 4 ft × 4 ft × (6" ÷ 12) = 4 × 4 × 0.5 = 8 cubic feet.
- 2
One 50-lb bag of play sand fills about 0.5 cubic feet (check the bag label).
- 3
Divide: 8 cu ft ÷ 0.5 cu ft per bag = 16 bags of 50-lb sand.
- 4
Or use 50-lb bags: 8 ÷ 0.5 = 16 bags. For 100-lb bags: 8 ÷ 1.0 = 8 bags.
Pro Tip
Use washed play sand (labeled "play sand"), not builder's sand or sandbox sand from big-box stores that isn't specifically labeled as play-safe. Play sand is washed to remove silica dust.
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