Free online tool • Play sand
Sandbox Sand Calculator
This sandbox sand calculator tells you how many bags of play sand fill your sandbox. Enter the sandbox size, or the diameter for a round one, choose how deep you want the sand, and get the number of 50 lb bags, cubic feet, tons and cost.
How Much Sand for a Sandbox?
How Much Sand for a 4x4 Sandbox?
A 4 × 4 ft sandbox filled 8 inches deep holds 4 × 4 × 0.667 = 10.7 cubic feet of sand. Play sand weighs about 96 lbs per cubic foot, so that is about 1,030 lbs — 21 bags of 50 lb play sand, or 23 bags with a little extra for topping up. At 6 inches deep the same sandbox takes 16 bags, and at 12 inches it takes 31.
Sandbox Sand Chart
| Sandbox size | Sand at 6 in | Sand at 8 in | Sand at 12 in |
|---|---|---|---|
| 4 × 4 ft | 16 bags | 21 bags | 31 bags |
| 5 ft round | 19 bags | 26 bags | 38 bags |
| 5 × 5 ft | 25 bags | 33 bags | 49 bags |
| 6 × 6 ft | 35 bags | 47 bags | 70 bags |
| 8 × 8 ft | 62 bags | 83 bags | 124 bags |
Bag counts are 50 lb bags of play sand, rounded up, before any extra allowance. For 40 lb bags, multiply by 1.25.
How Deep Should Sandbox Sand Be?
Most backyard sandboxes work best with 6 to 8 inches of sand, which is deep enough to dig and build in without reaching the bottom. Toddler sandboxes can be shallower, at about 4 inches. Leave 2 to 3 inches between the sand and the top of the frame so sand stays in the box. For sand used as safety surfacing under play equipment, public playground guidance calls for much more — at least 9 inches.
Best Sandbox Sand
Play sand
Play sand is washed and screened to remove clay, silt and debris, so it is soft, clean and molds well when damp. It is the standard sandbox sand and is sold in 50 lb bags at most home and garden stores.
Bulk washed sand
For large sandboxes, washed masonry sand from a sand yard is similar to play sand at a fraction of the cost. Ask for washed, screened sand and check it is free of sharp grit.
Sands to avoid
Avoid construction sand that has not been washed, which can contain silt and stain clothes, and avoid very fine dusty sand. Look for products sold for children's play, and keep the sandbox covered when not in use to keep out animals, leaves and rain.
How the Sandbox Sand Calculator Works
1. Sandbox area
Multiply length by width for a square or rectangular sandbox. For a round sandbox, the calculator uses π × radius²: a 5 ft round sandbox is 19.6 sq ft.
2. Volume of sand
Multiply the area by the sand depth in feet. 19.6 sq ft at 8 inches is 13.1 cubic feet.
3. Bags of play sand
Multiply cubic feet by 96 lbs and divide by the bag weight: 13.1 × 96 ÷ 50 = 25.2, so buy 26 bags. The sandbox sand calculator also adds the waste allowance you choose.
Sandbox Sand Cost
Bagged play sand costs about $5 to $8 per 50 lb bag, so a 4 × 4 sandbox costs roughly $110 to $170 to fill. Bulk washed sand delivered by the ton costs $40 to $60 per ton plus delivery — cheaper for big sandboxes, but most yards have a minimum load, so compare the total before ordering.
Related Sand Calculators
These tools use the same volume and density maths for neighbouring jobs:
- Sand calculator — any sand for any project
- Masonry sand calculator — bulk washed fine sand
- Landscape gravel calculator — pea gravel for play areas
- Gravel bags calculator — bag counts for gravel
- Garden gravel calculator — beds and borders around the yard
- Pool sand calculator — sand base for above-ground pools
Playground surfacing depths follow the CPSC Public Playground Safety Handbook, which lists minimum loose-fill depths for sand under play equipment.
Sandbox Sand FAQ
How much sand do I need for a 4x4 sandbox?
A 4 by 4 ft sandbox filled 8 inches deep needs about 10.7 cubic feet of play sand, which is about 21 bags of 50 lb. At 6 inches deep it needs about 16 bags.
How many bags of play sand do I need?
Multiply length by width by depth in feet to get cubic feet, then multiply by 2 to get the number of 50 lb bags, since each bag holds about half a cubic foot. Round up and add a few spare bags for topping up.
How deep should sand be in a sandbox?
Six to eight inches is ideal for most backyard sandboxes, with 2 to 3 inches of frame left above the sand to keep it in.
How much does a bag of play sand cover?
A 50 lb bag of play sand holds about half a cubic foot, which fills about 1 sq ft of sandbox 6 inches deep, or 0.75 sq ft at 8 inches deep.
Is it cheaper to buy sandbox sand in bulk?
For large sandboxes, yes. Bulk washed sand costs about $40 to $60 per ton plus delivery, against $200 to $320 per ton for bagged play sand, but small sandboxes rarely meet a sand yard's minimum load.