How deep should pea gravel be under a playground?

Fill to 12 inches. The U.S. Consumer Product Safety Commission's Public Playground Safety Handbook notes that a 12 inch initial fill compresses to about 9 inches over time, and 9 inches is the depth its tables work from for most loose-fill materials. Keep a border tall enough to hold the full 12 inches.

How much pea gravel do I need for a playground?

Add a 6 ft use zone around the equipment, multiply length × width × 1 ft of depth and divide by 27 for cubic yards, then multiply by about 1.35 for tons. A 20 × 15 ft play set becomes 32 × 27 ft = 864 sq ft, which is 32 cubic yards — about 43.2 tons of pea gravel at 12 inches.

How far should playground surfacing extend?

At least 6 feet in every direction from the edge of stationary equipment — the CPSC use zone. Swings need more: the zone in front and behind extends twice the height of the pivot point, so measure those separately and enter the larger footprint.

How much playground mulch do I need?

The same volume as any other loose fill: area × depth. Playground wood chips and engineered wood fiber are sold by the cubic yard or in bags of about 2 cubic feet, so the 864 sq ft example at 12 inches needs 32 cubic yards, or 432 bags. Bulk delivery is usually far cheaper above a few yards.

Can I put playground surfacing on concrete?

Not loose fill. The CPSC handbook warns against installing loose-fill materials over hard surfaces such as concrete or asphalt. Over a hard surface use a unitary surface such as poured-in-place rubber or rubber tiles that are tested for the fall height.

Landscaping

Playground Surfacing Calculator

Loose-fill surfacing under play equipment is a safety layer, so the depth comes from the U.S. Consumer Product Safety Commission rather than taste: fill to 12 inches, which settles to about 9 inches, over the equipment footprint plus a use zone of at least 6 feet on every side. Enter the equipment footprint and material for cubic yards, tons or bags, and the border you need to hold it in.

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The depth is a safety figure

Loose fill under play equipment is there to soften a fall, and it only works at depth. The U.S. Consumer Product Safety Commission's Public Playground Safety Handbook (Pub. No. 325) notes that an initial fill of 12 inches compresses to about 9 inches over time, and 9 inches is the depth its tables for loose-fill materials work from. That is why this calculator orders 12 inches by default and shows the settled depth.

Worked example: 20 × 15 ft play set

Step	Working	Result
Add the use zone	(20 + 12) × (15 + 12)	32 × 27 ft = 864 sq ft
Volume at 12 in	864 × 1 ÷ 27	32 yd³
Pea gravel by weight	32 × 1.35	43.2 tons
Wood chips in 2 cu ft bags	864 ÷ 2	432 bags
Border	2 × (32 + 27)	118 ft

The use zone

The surfacing has to cover more than the ground under the equipment. For stationary equipment the handbook's use zone extends at least 6 feet in every direction; swings need more in front and behind — twice the height of the pivot — so measure a swing set's zone separately and enter the larger footprint.

Choosing a material

Pea gravel lasts, drains and does not rot, but it is heavy to move and scatters onto paths. Size decorative beds with the pea gravel calculator.
Wood chips and engineered wood fiber are lighter and softer underfoot; they break down and need topping up. For garden beds use the mulch calculator.
Sand packs down when wet, so rake it often. A sandbox is a different job — see the play sand calculator.

Keep the border tall enough to hold the full 12 inches, lay landscape fabric under gravel and sand (the landscape fabric calculator counts the rolls), and never put loose fill over concrete or asphalt.

Get the Gravel & Stone Calculator app for Android

Estimate gravel, stone, sand, and mulch on the job site, save projects, and share quantities with your supplier.

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Frequently asked questions

How deep should pea gravel be under a playground?: Fill to 12 inches. The U.S. Consumer Product Safety Commission's Public Playground Safety Handbook notes that a 12 inch initial fill compresses to about 9 inches over time, and 9 inches is the depth its tables work from for most loose-fill materials. Keep a border tall enough to hold the full 12 inches.
How much pea gravel do I need for a playground?: Add a 6 ft use zone around the equipment, multiply length × width × 1 ft of depth and divide by 27 for cubic yards, then multiply by about 1.35 for tons. A 20 × 15 ft play set becomes 32 × 27 ft = 864 sq ft, which is 32 cubic yards — about 43.2 tons of pea gravel at 12 inches.
How far should playground surfacing extend?: At least 6 feet in every direction from the edge of stationary equipment — the CPSC use zone. Swings need more: the zone in front and behind extends twice the height of the pivot point, so measure those separately and enter the larger footprint.
How much playground mulch do I need?: The same volume as any other loose fill: area × depth. Playground wood chips and engineered wood fiber are sold by the cubic yard or in bags of about 2 cubic feet, so the 864 sq ft example at 12 inches needs 32 cubic yards, or 432 bags. Bulk delivery is usually far cheaper above a few yards.
Can I put playground surfacing on concrete?: Not loose fill. The CPSC handbook warns against installing loose-fill materials over hard surfaces such as concrete or asphalt. Over a hard surface use a unitary surface such as poured-in-place rubber or rubber tiles that are tested for the fall height.