How much sand do I need for a sandbox? 4x4 to 8x8
A 4 x 4 ft sandbox filled 6 inches deep holds 8 cubic feet of sand, which weighs about 799 lb and is 16 bags of 50 lb play sand; fill it 8 inches deep and it is 22 bags. A 6 x 6 sandbox at 8 inches takes 48 bags. Sand is heavy, roughly 100 lb per cubic foot, so the bag count climbs fast with size; the tables run from 3 x 3 to 8 x 8 ft at 6, 8 and 10 inches.
Sand by sandbox size and depth
Inside dimensions of the frame, filled level to the depth shown. Sand at 1.6 tonnes per cubic metre (100 lb per cubic foot), which makes a 50 lb bag about 0.5 cubic feet. No waste allowance: sand does not get cut, but buy one bag more than the table if you like it full.
| Sandbox | Cubic feet | Weight (lb) | Bags (50 lb) |
|---|---|---|---|
| 3 x 3 ft | 4.5 | 449 | 9 |
| 4 x 4 ft | 8 | 799 | 16 |
| 4 x 6 ft | 12 | 1,199 | 24 |
| 5 x 5 ft | 12.5 | 1,249 | 25 |
| 6 x 6 ft | 18 | 1,798 | 36 |
| 8 x 8 ft | 32 | 3,196 | 64 |
| Sandbox | Cubic feet | Weight (lb) | Bags (50 lb) |
|---|---|---|---|
| 3 x 3 ft | 6 | 599 | 12 |
| 4 x 4 ft | 10.7 | 1,065 | 22 |
| 4 x 6 ft | 16 | 1,598 | 32 |
| 5 x 5 ft | 16.7 | 1,665 | 34 |
| 6 x 6 ft | 24 | 2,397 | 48 |
| 8 x 8 ft | 42.7 | 4,262 | 86 |
| Sandbox | Cubic feet | Weight (lb) | Bags (50 lb) |
|---|---|---|---|
| 3 x 3 ft | 7.5 | 749 | 15 |
| 4 x 4 ft | 13.3 | 1,332 | 27 |
| 4 x 6 ft | 20 | 1,998 | 40 |
| 5 x 5 ft | 20.8 | 2,081 | 42 |
| 6 x 6 ft | 30 | 2,997 | 60 |
| 8 x 8 ft | 53.3 | 5,327 | 107 |
How the numbers are worked out
Length x width x depth in feet gives cubic feet: 4 x 4 x 0.5 = 8 cubic feet at 6 inches. Multiply by 100 lb per cubic foot for the weight, divide by 50 for bags, round up. The sand and gravel calculator does it for any box, including a round one if you give it the area (3.14 x radius²).
Bags or bulk?
Up to about 20 bags, bagged play sand from the hardware store is the practical choice: it is clean and it fits in a car. Above that, a landscape yard sells washed sand by the half yard or the ton, which for a big 8 x 8 box is far cheaper; a half yard is 13.5 cubic feet, roughly 27 bags. Ask for play or beach sand and check it for stones.
Metric: sandpits in litres and 25 kg bags
Play sand in 25 kg bags; a 1.2 x 1.2 m pit filled 15 cm deep takes about 216 litres, which is 14 bags.
| Sandpit | Depth | Litres | Weight (kg) | Bags (25 kg) |
|---|---|---|---|---|
| 1 x 1 m | 15 cm | 150 | 240 | 10 |
| 1.2 x 1.2 m | 15 cm | 216 | 346 | 14 |
| 1.5 x 1.5 m | 15 cm | 337 | 540 | 22 |
| 2 x 2 m | 15 cm | 600 | 960 | 39 |
| 1 x 1 m | 20 cm | 200 | 320 | 13 |
| 1.2 x 1.2 m | 20 cm | 288 | 461 | 19 |
| 1.5 x 1.5 m | 20 cm | 450 | 720 | 29 |
| 2 x 2 m | 20 cm | 800 | 1,280 | 52 |
Before you fill it
- Landscape fabric under the sand keeps soil and weeds out and lets rain drain; a cover on top keeps cats and leaves out.
- Build the frame from untreated cedar or a modern treated timber rated for ground contact; older CCA-treated wood is not for a sandbox.
- Gravel under the fabric (2 inches) helps drainage on clay soil; the shed base guide shows how little it takes for a small pad.
Frequently asked questions
- How much sand do I need for a 4x4 sandbox?
- 8 cubic feet (16 bags of 50 lb, about 799 lb) at 6 inches deep, 10.7 cubic feet (22 bags) at 8 inches and 13.3 cubic feet (27 bags) at 10 inches. Six to eight inches is plenty for digging and castles.
- How many 50 lb bags of sand do I need for a sandbox?
- A 50 lb bag of play sand is about 0.5 cubic feet, so divide the volume of the sandbox in cubic feet by 0.5. For a 5 x 5 sandbox at 8 inches (16.7 cubic feet) that is 34 bags. The tables have every common size.
- How much sand for a turtle sandbox?
- The classic green turtle holds about 1.6 cubic feet of sand when filled 4 inches deep over its roughly 30 inch sand area: 4 bags of 50 lb, about 163 lb. One bag fewer leaves room for toys and buckets.
- How deep should the sand be in a sandbox?
- 6 to 8 inches for toddlers, up to 10 or 12 for older children who dig tunnels. Leave 2 to 3 inches between the sand and the top of the frame so it does not spill over the sides, and put a weed membrane or landscape fabric underneath so the sand stays clean and drains.
- What kind of sand for a sandbox?
- Washed play sand, sold in bags for exactly this: rounded, screened and dust-free. Builders sand and masonry sand are sharp and dusty; paver sand and polymeric sand are not for children. Bulk sand from a yard is cheaper for a large box, but ask for washed play or beach sand, not concrete sand.
- How much does a sandbox of sand weigh?
- About 100 lb per cubic foot dry, so a 6 x 6 sandbox 8 inches deep holds 2,397 lb of sand, and an 8 x 8 at 10 inches over 5.3 thousand lb. That matters on a deck or balcony: check what the structure can carry.
More guides
- How much gravel do I need for a driveway?
Cubic metres, tonnes and bulk bags of gravel for typical driveway sizes at 50, 75 and 100 mm depth, with the imperial equivalents in cubic yards and tons.
- How much does a cubic yard of gravel weigh?
A cubic yard of gravel weighs about 1.2 to 1.4 US tons; sand and topsoil differ. Pounds and tons per yard, yards per ton, and tonnes per cubic metre for each material.
- How much gravel for a shed base? 6x8 to 12x16 ft
Cubic yards, tons and bags of gravel for 6x8, 8x10, 10x12 and 12x16 ft shed bases at 4 and 6 inches, why the base runs past the shed, and metric sizes in tonnes.
- How much sand and gravel do I need under pavers?
Gravel base at 4 or 6 inches and 1 inch of bedding sand for 100 to 500 sq ft of pavers: cubic yards, tons and bags, plus the metric patio in tonnes and bulk bags.
Last updated 2026-09-12. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.