What is the Play Sand Calculator?
The Play Sand Calculator helps you figure out exactly how much sand to buy for a sandbox, play area, or sand pit. Buying too little means a second trip to the store; buying too much leaves bags wasting in the shed. Enter the dimensions of your area and the calculator returns the volume, the total weight in pounds, and the number of bags you need.
How to use it
Measure your sandbox and enter the length and width in feet, and the desired depth in inches. Most play sandboxes use a depth of 4–8 inches. The default density of \(100\ \text{lb/ft}^3\) is typical for dry play sand; adjust it if your supplier lists a different value. Set the bag size to match the bags you plan to buy (commonly 50 lb).
The formula explained
First the area is multiplied by depth to get volume in cubic feet, converting inches to feet by dividing by 12:
$$V = L \times W_d \times \frac{D}{12}$$Weight is volume times density \(\rho\), and the number of bags is the weight divided by bag size \(B\), rounded up:
$$W = V \times \rho, \qquad N = \left\lceil \frac{W}{B} \right\rceil$$Here \(L\) and \(W_d\) are in feet, \(D\) is in inches, \(\rho\) is in pounds per cubic foot, and \(B\) is the bag weight.
Worked example
For a 10 ft × 10 ft sandbox filled 6 inches deep with 50 lb bags of 100 lb/ft³ sand:
$$V = 10 \times 10 \times \frac{6}{12} = 50\ \text{ft}^3$$$$W = 50 \times 100 = 5000\ \text{lb}$$$$N = \left\lceil \frac{5000}{50} \right\rceil = 100\ \text{bags}$$FAQ
How deep should sandbox sand be? A depth of 4 to 8 inches is comfortable for play and digging; deeper layers cost more and rarely add benefit.
What does play sand weigh? Dry play sand is roughly 100 lb per cubic foot. Wet or compacted sand can weigh more.
Why is the bag count rounded up? You cannot buy a fraction of a bag, so the result rounds up to ensure you have enough sand.
