Sandbox Volume Calculator

A circle's area only needs one dimension — its diameter — which the calculator takes from the Length field and halves to get the radius before applying the standard circle-area formula. The Width field only applies to the rectangular calculation, so switching to circular makes it irrelevant to the area and volume results regardless of what value is entered there.

Bagged sand from a hardware store is typically priced and measured in cubic feet, but bulk sand delivery from a landscaping or sand supplier is almost always priced by the cubic yard. Providing both units lets you get an accurate quote whichever purchasing route you're considering.

That range is a commonly recommended depth for comfortable, safe digging and building play — deep enough for kids to dig, mold, and bury toys without immediately hitting the bottom, but not so deep that it becomes impractical to fill and maintain. A shallower depth works for very young children with lighter play needs, while older kids doing more elaborate sand construction may prefer the deeper end of that range.

Comparing the Bag Cost and Bulk Cost outputs directly answers this for your specific volume — bagged sand is usually more convenient for smaller sandboxes with no delivery minimum, while bulk delivery typically becomes more cost-effective once volume climbs into the range of a full cubic yard or more, since bulk pricing avoids the per-bag packaging markup.

It applies a general guideline of about 25 square feet of play area per child, which gives a reasonable comfort estimate for typical sandbox play but isn't a strict capacity limit — younger children playing side by side often use less individual space than older kids engaged in more elaborate building projects. Treat it as a loose planning guide rather than a hard capacity limit.