Rubber Mulch Calculator

Calculate rubber mulch by cubic feet, pounds and 0.8 cu ft bags for a playground or a landscape bed, with the playground depth set from the CPSC fall height table.

By CalcBuilt Editorial TeamUpdated September 9, 2026Formulas checked against manufacturer specs, see how we calculate.

Quick answer: Rubber mulch is sold by volume and weight, so multiply area by depth in feet for cubic feet, then by about 25 lb per cubic foot. A 20 x 20 ft playground use zone at the 8 in CPSC install depth needs 266.7 cubic feet, which is 6,667 lb or 334 bags of 0.8 cu ft.

Your measurements

Cross-section: volume is the area covered times the depth of the layer.

Where it goesPlayground depth comes from CPSC Table 2, not from looks. A landscape bed uses the depth you enter, because rubber never breaks down and does not need topping up.LengthftFor a playground, measure the use zone, not the equipment. The zone runs 6 ft past the structure on every side, and farther in front of swings.WidthftFall height (playground)ftThe highest standing or sitting surface: the top deck, the top rung, or the swing seat at rest. It sets the depth the surfacing has to protect.Bed depth (landscape)in1.5 to 2 in covers the soil for good. Wood mulch is laid at 3 in because a third of it rots away each year, and rubber does not.Price per 0.8 cu ft bag (optional)$Bagged shredded rubber is typically $5 to $9 per 0.8 cu ft bag in 2026 US retail, several times bagged wood mulch per cubic foot.Bulk price per pound (optional)Playground rubber sold by the super sack or pallet is typically $0.35 to $0.60 per pound in 2026, freight extra. Used only when no bag price is entered.

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Results

Rubber mulch needed: 266.7 cu ft; 400 sq ft at 8 in installed
Installed depth: 8 in; 6 in maintained protects a 10 ft fall height per CPSC Table 2, and yours is 8 ft
Weight: 6,667 lb; 3.33 tons at about 25 lb per cubic foot; suppliers quote playground rubber by weight
0.8 cu ft (23 L) bags: 334 bags; About 20 lb per bag, so this is where most people switch to bulk
Pallets or super sacks: 7 pallets; A pallet holds 50 bags; in bulk this is about 3.6 super sacks of 75 cu ft

Rubber Mulch formula

Cubic feet = Length (ft) x Width (ft) x Depth (in) / 12
Playground depth = 8 in installed, 6 in maintained (CPSC Table 2, 10 ft fall height)
Pounds = Cubic feet x 25
Bags = Cubic feet / 0.8   (about 20 lb per bag)

Worked example

A swing set and slide with a use zone measuring 24 x 20 ft is 480 sq ft. At the 8 in install depth: 480 x (8 / 12) = 320 cubic feet, or 8,000 lb. That is 400 bags of 0.8 cu ft, 8 pallets, or about 4.3 super sacks of 75 cu ft. Bagged at $7 a bag it is $2,800, which is why playground jobs ship in bulk.

A 10 x 4 ft foundation bed is a different scale. At 2 in deep: 40 x (2 / 12) = 6.67 cubic feet, or 9 bags weighing about 167 lb. At $7 a bag that is $63, and it does not need doing again in three years.

Quick reference

Rubber mulch per 100 sq ft by depth, at 25 lb per cubic foot
Depth	Cubic feet	0.8 cu ft bags	Pounds
1.5 in	12.5	16	313
2 in	16.7	21	417
3 in	25.0	32	625
4 in	33.3	42	833
6 in	50.0	63	1,250
8 in	66.7	84	1,667

Playground depth is an impact number, not a look

The depth under play equipment comes from a fall height, not from taste. CPSC Table 2 puts rubber mulch at 8 inches installed and 6 inches maintained, and that combination is rated to a 10 foot fall height. Measure the fall height as the highest surface a child stands or sits on, then spread the install depth across the whole use zone, which reaches 6 feet past the structure and much farther in front of swings. Rubber earns its price here: pea gravel at 9 inches maintained protects only 5 feet.

Maintenance is where these surfaces fail. Rubber does not compress the way wood fiber does, but it kicks out under swings and at slide exits, and the thin spot is exactly where children land. Mark the install depth on the equipment posts, rake material back monthly, and add wear mats at the two hot spots. Products sold as playground rubber carry an ASTM F1292 critical height rating; shredded tire from a landscape yard does not, and an installed surface should be field tested to ASTM F3313.

Base, border and what rubber does in a bed

Under a playground, build the layers: compacted subgrade sloped to drain, 3 to 6 inches of drainage stone, a geotextile cloth, then the rubber. Skip the stone and fabric and the mulch mixes with soil, holds water and packs down. Contain it with a timber, concrete or rubber curb; loose fill that has nothing to stop it migrates out of the zone every season.

In a landscape bed the calculation is simpler and the depth is smaller. Weed the bed first, because rubber is not a growing medium and you will not be pulling weeds out of it later. Spread 1.5 to 2 inches, and edge the bed so runoff cannot float it onto the walk. Understand the trade before buying: it holds its color for years and never needs topping up, but it adds nothing to the soil, it heats up in direct sun, and taking it out later means screening every square foot.

What this calculator leaves out

The drainage stone, geotextile and the graded subgrade under playground surfacing, plus the containment curb, wear mats under swings and slide exits, and ASTM F1292 and F3313 testing. In a bed it leaves out edging, weed removal, and the freight charge on pallets, which for playground quantities often rivals the delivery fee on a load of stone.

Code limits that apply

CPSC Handbook Table 2checked
Rubber mulch 8 in installed, 6 in maintained, rated to a 10 ft fall height
If you miss it: Surfacing raked thin under a swing stops protecting the fall it was bought for
ASTM F3012
Loose-fill rubber for playgrounds is tested to F3012, and its critical height to F1292
If you miss it: Untested shredded tire from a landscape yard has no critical height rating at all
ASTM F3313
Field impact test of the surfacing after installation, then on a maintenance schedule
If you miss it: A compacted or thin spot passes visual inspection and fails the field drop test
CPSC Handbook 5.3
Use zone 6 ft beyond equipment in all directions; swing zones twice the pivot height front and back
If you miss it: Surfacing stops at the deck edge and a child lands on grass or asphalt
ASTM F1951
Accessible routes need surfacing that is firm and stable under a wheelchair
If you miss it: Loose fill that is not compacted and tested blocks the accessible route to the equipment

Provision	Limit	If you miss it
CPSC Handbook Table 2checked	Rubber mulch 8 in installed, 6 in maintained, rated to a 10 ft fall height	Surfacing raked thin under a swing stops protecting the fall it was bought for
ASTM F3012	Loose-fill rubber for playgrounds is tested to F3012, and its critical height to F1292	Untested shredded tire from a landscape yard has no critical height rating at all
ASTM F3313	Field impact test of the surfacing after installation, then on a maintenance schedule	A compacted or thin spot passes visual inspection and fails the field drop test
CPSC Handbook 5.3	Use zone 6 ft beyond equipment in all directions; swing zones twice the pivot height front and back	Surfacing stops at the deck edge and a child lands on grass or asphalt
ASTM F1951	Accessible routes need surfacing that is firm and stable under a wheelchair	Loose fill that is not compacted and tested blocks the accessible route to the equipment

Rows marked checked produce a warning in the results when an entry crosses the limit. The others are on the plans or on site and this calculator does not test them. Local amendments can be stricter; the adopted edition and the inspector govern.

Mistakes that cost money

Installing to the 6 in maintained depth: it drops below the tested depth under swings within weeks, so spread 8 in and rake it back monthly.
Buying by cubic yards from a supplier who prices by the pound; convert at about 675 lb per cubic yard before comparing quotes.
Rubber laid straight on turf or bare soil sifts dirt up into the layer, so it needs a drainage base and a geotextile under it.
No border: rubber floats, and one downspout or a heavy storm carries a bed of it into the lawn.
Rubber mulch near a wildland edge burns hot and is hard to put out, so fire-prone lots should use stone in the defensible space.
Dark rubber in full sun runs far hotter than wood mulch; a bare-foot play area needs shade or a lighter color.

Key facts

CPSC Table 2 lists rubber mulch at 8 in installed and 6 in maintained, which protects a 10 ft fall height; wood chips need 9 in maintained for the same height.
Rubber does not compress like other loose fill, but it displaces under swings and at slide exits, which is where the depth has to be checked.
A playground use zone runs 6 ft beyond the equipment in every direction, and the zone in front of a swing is twice the pivot height.
Bagged shredded rubber runs about 25 lb per cubic foot, so a 0.8 cu ft bag weighs about 20 lb and a pallet of 50 bags is roughly half a ton.
Rubber mulch is laid 1.5 to 2 in deep in beds because none of it rots away, against 3 in for wood mulch that is topped up yearly.

Frequently asked questions

How deep should rubber mulch be under a swing set?

8 in installed, kept at 6 in through the season. CPSC Table 2 rates that depth for a 10 ft fall height. Spread it across the full use zone, which is 6 ft beyond the structure and farther in front of swings.

How many bags of rubber mulch do I need?

Divide the cubic feet by 0.8. A 100 sq ft bed at 2 in deep is 16.7 cubic feet, so 21 bags. A 400 sq ft playground zone at 8 in is 267 cubic feet, or 334 bags, which is a bulk order.

How much does rubber mulch weigh?

About 25 lb per cubic foot bagged, so a 0.8 cu ft bag weighs roughly 20 lb and a cubic yard is about 675 lb. Bulk playground rubber is usually priced by the pound.

Is rubber mulch worth the money in a garden bed?

It costs several times bagged wood mulch up front and lasts many years, so the arithmetic favors rubber only if you plan to leave the bed alone. It adds no organic matter, runs hot in full sun, and cannot be dug into the soil, so keep it out of vegetable beds and away from areas you replant often.

Sources and references

Public Playground Safety Handbook, Table 2 loose-fill depths and use zones (U.S. Consumer Product Safety Commission)
ASTM F1292 Standard Specification for Impact Attenuation of Surfacing Materials Within the Use Zone of Playground Equipment (ASTM International)
GroundSmart rubber mulch installation depths by application (GroundSmart)
C075 Guide to Mulches (shredded tire products in the landscape) (Washington State University Extension)

Next steps for this project

The usual order for a landscaping & outdoor project. See all landscaping & outdoor calculators.

Results are estimates based on standard formulas and typical product specifications. Confirm quantities with your supplier and local code before ordering.