How much sand for a 4×4 sandbox?
A 4 × 4 ft sandbox filled 6 inches deep needs 8 cubic feet of sand (0.31 cubic yards), about 840 pounds, or 17 bags of 0.5 cu ft play sand at roughly 50 lb each.
How to work it out
- 4 ft × 4 ft = 16 sq ft
- 16 sq ft × 6 in ÷ 12 = 8 cu ft ÷ 27 = 0.3 cu yd
- 0.3 cu yd compacted × 1 = 0.3 cu yd loose × 1.35 tons/cu yd = 0.4 tons
- + 5% waste = 0.42 tons
- Effective rate: ≈ 1.42 tons per cu yd compacted
- 8.4 cu ft loose ÷ 0.5 cu ft per bag = 17 bags
A 4 × 4 box is the most common backyard sandbox: big enough for two small children, small enough to cover with a single tarp or lid. Six inches of sand gives room to dig without needing a delivery, and the whole fill fits in the back of a car in two or three trips.
Adjust for your project
More options: Compaction · Waste · Bag price …
- Bags of that size
- 17 bags · 0.5 cu ft bag
- For a sandbox, choose washed play sand sold for that purpose, and leave a few inches of freeboard below the rim.
Play sand 6 in deep for common sandbox sizes (4 ft long, width varies)
| Width | Bags of that size | Sand volume (loose) | Approx. weight |
|---|---|---|---|
| 3 ft | 13 bags | 0.23 cu yd | 0.32 tons |
| 4 ft | 17 bags | 0.31 cu yd | 0.42 tons |
| 5 ft | 21 bags | 0.39 cu yd | 0.53 tons |
| 6 ft | 26 bags | 0.47 cu yd | 0.63 tons |
| 8 ft | 34 bags | 0.62 cu yd | 0.84 tons |
What to know about a 4×4 sandbox
Most 4 × 4 kits and home-built boxes are 10–12 in tall, from two courses of 2×6 lumber. Fill to 6–8 in and leave a few inches of rim so sand stays in the box when kids dig; at 8 in deep the count goes up to about 23 bags (see below).
Buy sand sold as play sand: it is washed and screened so it is soft and free of sharp stone. Concrete sand and masonry sand from a landscape yard are cheaper by the ton but coarser or dustier, and at under half a ton, the bags are the easier buy anyway.
Drainage is the common mistake. A box built on a patio or with a solid plywood floor holds rainwater and the sand goes sour. Build it on soil or gravel with landscape fabric stapled across the bottom, so water drains out and weeds don’t grow in.
Keep it covered. A fitted lid or cover keeps out rain, leaves and cats; an uncovered box needs the top inch raked or replaced now and then, so a few spare bags are worth keeping. Planning climbing equipment near it? Fall zones need far deeper loose fill — see how much pea gravel for a 10×10 play area.
Different size? Use the full Sand Calculator.
What you’ll need
- Sandbox coverBudget price
Keeps rain, leaves and animals out of the sand between uses.
See options on Amazon (opens in a new tab) - Landscape fabric (woven or heavy non-woven)Budget price
Separates stone from soil under gravel and rock. Less useful under wood mulch, which breaks down into soil on top of it anyway.
See options on Amazon (opens in a new tab) - Square-point transfer shovelBudget price
Flat blade for scooping gravel, soil and sand off a driveway pile — a round shovel leaves too much behind.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How much sand for a 4×4 sandbox 8 inches deep?
About 23 bags of 0.5 cu ft, 0.41 cubic yards or roughly 1,120 pounds of play sand.
How much sand for a 4×8 sandbox?
At 6 inches deep, about 34 bags of 0.5 cu ft (0.62 cubic yards, roughly 1,680 pounds). That is twice the 4 × 4 box.
How many 1 cu ft bags of sand for a 4×4 sandbox?
9 bags of 1 cu ft fill a 4 × 4 ft box 6 inches deep. Larger bags are fewer trips but can weigh close to 100 lb each.
Sources
- ICPI Tech Spec 2 — Construction of Interlocking Concrete Pavements (opens in a new tab) — Bedding sand to ASTM C33, screeded to a nominal 1 in; no masonry sand or stone dust
- CPSC — Outdoor Home Playground Safety Handbook (opens in a new tab) — Sand as a fall surface: 9 in for equipment up to 5 ft
- Gravel Monkey — How many tons of gravel in a dump truck? (opens in a new tab) — Typical payloads: single-axle about 6–10 tons, tandem 12–16, tri-axle 18–25; gravel hits the weight limit before the bed is full.