🛝How much playground mulch does your play area need?

✓ Tested & verified Updated: Aug 6, 2026 How we calculate this

Playground wood fiber calculator

Length ft

Width ft

Depth

Bag size

16.7 cubic yards≈ 4.2 tons

= 450 cu ft · about 225 bags (2 cu ft)

Weight, dry: 8,333 lb
Loads in a half-ton pickup: 5
One cubic yard covers: 36 sq ft at this depth

Depth is set by the fall height of the tallest platform, not by the size of the area.

Try also

How much playground mulch do you need?

A 30 × 20 ft play area at the 9-inch depth that pairs with a 7-foot fall height needs 450 cubic feet — 16.7 cubic yards, or about 8,300 lb of engineered wood fiber. Area × depth ÷ 27 is the same arithmetic as a garden bed; what changes is that the depth is not yours to choose.

The CPSC handbook sets loose-fill depth by the fall height of the highest accessible part of the equipment: 6 inches to roughly 5 feet, 9 inches to 7 feet and 12 inches to 12 feet for engineered wood fiber. Measure to the top of the highest platform or the peak of a swing’s designated play surface, not to the top of the frame.

Then add for compaction. Wood fiber packs down under traffic within weeks, so order 20 to 25 percent over the calculated volume and rake the surface back to the marked depth each spring — a use zone worn down to 4 inches is no longer the surface the equipment was rated against.

Everything on a playground order follows from one measurement, and it is not the size of the area. It is the fall height: the vertical distance from the highest surface a child can stand on to the protective surfacing below. That number sets the depth, and the depth sets the volume.

Measure the fall height first, read the depth off the table, then measure the use zone — six feet out from stationary equipment, and twice the pivot height fore and aft of any swing.

Fall height	EWF depth	600 sq ft needs	Weight
Up to 5 ft	6 in	11.1 cubic yards	5,600 lb
Up to 7 ft	9 in	16.7 cubic yards	8,300 lb
Up to 12 ft	12 in	22.2 cubic yards	11,100 lb

Add 20 to 25 percent to any of those figures on the first fill. Wood fiber that has been walked on for a month occupies noticeably less space than the pile the truck tipped out.

Frequently asked questions

How deep does playground mulch need to be?

Six inches of engineered wood fiber covers a fall height of about 5 feet, 9 inches covers 7 feet, and 12 inches covers up to 12 feet. Those are the CPSC loose-fill figures and they describe the depth maintained in service, not the depth on delivery day — which is why the material is ordered with a compaction allowance on top.

Is engineered wood fiber the same as landscape mulch?

No. Engineered wood fiber is milled to a controlled fibre length from clean wood with no bark, no leaf and no chemical treatment, and it is tested to ASTM F1292 for impact attenuation at a stated depth. Landscape bark and shredded hardwood have never been tested, contain bark that breaks into slippery plates, and are not accessible surfacing under the ADA guidelines.

How big should the safety surfacing area be?

The use zone extends at least 6 feet in every direction from stationary equipment, and for swings it runs forward and back to twice the height of the pivot bar. A 10 ft swing bar therefore needs 20 feet of surfaced ground in front and behind, which is usually the single biggest driver of the volume on this page.

How often does playground mulch need topping up?

Check the depth at the highest-traffic points — under swings and at slide exits — every few months and top up annually. Those spots wear to bare ground first and are exactly where the fall height is greatest. A full replacement is normally needed every three to five years as the fibre breaks down.

Does rubber mulch work out cheaper?

Not per cubic yard, but it lasts longer and needs less depth for the same fall height, so the ten-year cost is closer than the sticker suggests. Rubber weighs about 800 lb per cubic yard against 500 for wood fiber, does not decompose, and does not need annual topping up — but it holds heat in full sun and costs three to four times as much up front.

Can I put playground mulch straight on grass?

Strip the turf first. Grass and topsoil under loose fill turn to mud, the fibre mixes into it and the effective depth drops within one wet season. Excavate to the full surfacing depth, lay geotextile fabric, and provide drainage — standing water under wood fiber accelerates decomposition faster than the traffic does.

How we calculate this

Volume is area × depth ÷ 12 ÷ 27, the same formula every material on this site uses. Weight uses 500 lb per cubic yard for engineered wood fiber, the midpoint of the 400–650 lb range in our density table; a cubic yard covers 36 sq ft at 9 inches and 27 sq ft at 12. Depth-by-fall-height figures are the loose-fill values published in the US Consumer Product Safety Commission Public Playground Safety Handbook (Pub. 325), read together with ASTM F1292 impact-attenuation testing — they are a safety standard, not a landscaping preference, and this calculator does not substitute for the surfacing specification supplied with your equipment.

Worked example

With Length ft 30, Width ft 20, Diameter ft 12, Base ft 20, Height ft 12, Area sq ft 300, Ring diameter ft 6, Gap around trunk (in) 4, Depth 9, Bag size 2 cu ft — Shredded hardwood, the default US mulch bag, this page works out 16.7 cubic yards ≈ 4.2 tons. = 450 cu ft · about 225 bags ( 2 cu ft )

Weight, dry8,333 lb
Loads in a half-ton pickup5
One cubic yard covers36 sq ft at this depth

Sources: