How to calculate a playground mulch
Safe playground surfaces use a deep layer of loose fill that meets safety guidelines for the equipment height.
- Measure the fall zone around each piece of equipment.
- Choose a depth that matches the equipment fall height, using the manufacturer and safety guidance.
- Calculate the volume, then add extra for compression.
- Top up each year, because loose fill compacts and scatters.
Worked example
For a typical playground mulch with length 20 ft, width 20 ft, depth 9 in, the volume is 300.00 cubic feet. Divide by 27 for 11.11 cubic yards. With a 10 percent allowance, plan for 12.22 cubic yards.
In wood chips, 11.11 cubic yards weighs about 2.78 US tons at a planning value of 500 pounds per cubic yard.
Playground Mulch sizes and quantities
These common sizes are calculated with the same formula as the tool above, so you can find your number quickly.
| Size | Cubic feet | Cubic yards | With 10 percent extra | US tons |
|---|---|---|---|---|
| 10 by 10 ft, 6 in | 50.00 | 1.85 | 2.04 | 0.46 |
| 20 by 20 ft, 9 in | 300.00 | 11.11 | 12.22 | 2.78 |
| 30 by 30 ft, 9 in | 675.00 | 25.00 | 27.50 | 6.25 |
| 40 by 40 ft, 12 in | 1,600.00 | 59.26 | 65.19 | 14.81 |
Tips
- Use engineered wood fiber or other material made for playgrounds.
- Check the depth with a ruler each season.
- Install an edge border to keep the fill in.
Common mistakes to avoid
- Using a thin layer that does not cushion a fall.
- Using ordinary landscape mulch with splinters.
- Never topping it up.
These figures are planning estimates. Real material varies in moisture, size, and compaction, so confirm weights and order quantities with your supplier.
Frequently asked questions
How many cubic yards do I need for a playground mulch?
Multiply the dimensions in feet and divide by 27. The example above, length 20 ft, width 20 ft, depth 9 in, needs 11.11 cubic yards before waste.
How much extra should I order?
Add 5 to 10 percent for waste. Add more if the ground is uneven or the material is loose.
Can I enter inches and feet together?
Yes. Each box has its own unit selector, so you can mix feet and inches.
How much does playground mulch material weigh?
11.11 cubic yards of wood chips weighs about 2.78 US tons as a planning value.