Sandboxes are a great addition to any backyard playset, but it can be a little tough to tell how much sand you actually need to cover the sandbox area. Whether you are just installing your first sandbox, building a DIY sandbox, or replacing the sand in your current one, you can use our calculator below to figure out how many 50 lb. bags of sand you need for the job. We’ve also outlined the specific calculation below in case you’re curious.

Step-by-Step Calculation: How Much Sand You Need In Your Sandbox

What Shape of Sandbox Do You Have?

To determine the number of sand bags you need, we have to figure out the volume of sand to fill your sandbox, measured in cubic feet (most standard sand bags are 0.5 cubic feet). Heading back to high school geometry class, the shape of your sandbox will determine how to calculate that volume.

For rectangular sandboxes, use this formula to get the area first:

Length x Width = Area

For round sandboxes, it’s a bit more complicated. Take the diameter of the sandbox and divide it by two to get the radius. You’ll then square the radius and multiply by Pi to get the area.

Area = π*r^2

How Deep Do You Want the Sand?

We recommend 4-6 inches of sand in your sandbox. Once you’ve figured out the depth, use this formula to get the volume in cubic feet:

Area x Depth = Volume in cubic feet

Don’t forget to convert your depth from inches to feet! So, for example, 6 inches equals 0.5 feet.

Convert Cubic Feet to Number of Bags

Like I said earlier, each sand bag should be 0.5 cubic feet. So, if you need 15 cubic feet of sand as an example, you will need to buy 30 bags of sand.

If you’re not sure which type of sand to get, we like Quikrete play sand which you can order online or probably find at Lowes, Home Depot, or another local hardware store. You can also head over to that DIY sandbox article that we linked above for more instructions.

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Final Comments

There you have it, a simple calculation to determine how much sand you need for your new sandbox. For more tips on how to keep your sandbox clean and safe, head over to our sandbox maintenance checklist.

Let us know if you have any questions and good luck!

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