What Is the Sandbox Sand Calculator?
This tool estimates how much play sand you need to fill a sandbox or sand pit. It computes the cubic volume of sand from the box dimensions and the desired sand depth, then converts that volume to weight using the density of sand so you know exactly how many pounds, tons, or 50 lb bags to buy.
How to Use It
Enter the inside length and width of your sandbox in feet, and the depth of sand you want in inches. The default density of 100 lb/ft³ is typical for dry play sand, but you can adjust it for your specific material. Click calculate to see total volume, weight, and the number of bags required.
The Formula Explained
First the depth is converted from inches to feet by dividing by 12. Volume is then length × width × depth (in feet), giving cubic feet. Weight equals volume × density. For example, a sandbox 6 ft long, 6 ft wide, filled 6 in deep contains
$$6 \times 6 \times 0.5 = 18 \text{ ft}^3.$$At 100 lb/ft³ that is 1,800 lb of sand — about 0.9 US tons, or 36 fifty-pound bags.
FAQ
How deep should sand be in a sandbox? Most playboxes use 3–6 inches; deeper sand allows more digging and shaping.
What density should I use? Dry play sand is roughly 90–110 lb/ft³; use 100 lb/ft³ as a safe estimate, or the figure on your supplier's bag.
Why buy a little extra? Sand settles and compacts over time, so adding 5–10% beyond the estimate keeps the box topped up.
