Rubber Mulch Calculator

1. Enter the area to cover in square feet.
2. Pick a use, landscape or playground, which sets a depth.
3. Override the depth to match your product certificate if needed.
4. Pick a bag size and read the bags, volume and weight.

Here is what each result line means:

Comparing with wood mulch? Size that with the mulch calculator.

A rubber mulch calculator works out how many bags of recycled rubber mulch cover an area at a chosen depth, plus the volume and weight. It serves both landscaping and playground safety surfacing.

Rubber mulch is shredded recycled tire rubber. In beds it is a long-lasting mulch that does not decompose; under play equipment it is an impact-absorbing loose-fill surface rated by fall height.

It uses the same area-and-depth math as the mulch calculator, with rubber bag sizes and the playground depth rule.

Area times the depth in inches divided by 12 gives cubic feet; divided by 324 it gives cubic yards. A bag covers its cubic feet times 12, divided by the depth.

1. Cubic feet = area in square feet times depth in inches, divided by 12.
2. Bags = cubic feet divided by the bag size, rounded up.
3. Weight = cubic feet times about 28 pounds, since rubber mulch is roughly 0.38 tons per cubic yard.

A 0.8-cubic-foot bag is about 24 pounds and a 1.5-cubic-foot bag about 40. Bag size and weight vary by brand, so check the bag.

A 200 sq ft landscape bed at 2 in, in 0.8 cu ft bags.

Calculation: Volume = 200 x 2 / 12 = 33.3 cubic feet, which is 42 bags of 0.8 cubic feet, about 933 pounds.

A 300 sq ft playground at 6 in for a 10-foot fall height is 150 cubic feet, about 100 bags of 1.5 cubic feet or 5.56 cubic yards.

Depth and Use

A landscape bed is about 2 inches; a playground needs 6 inches of loose rubber for a 10-foot fall height. Depth drives the volume directly.

Fall Height

Under play equipment, the surfacing depth must match the equipment fall height per the product ASTM F1292 test. Taller equipment needs a deeper, tested surface.

Compression

Loose fill compresses about 25 percent over time, so a playground must be topped up to keep its rating. Install a little proud of the target depth.

Bag Size

Bags are commonly 0.8 or 1.5 cubic feet and vary by brand, which changes the count. Check the bag rating.

Use Zone

A playground surface must extend across the whole use zone around the equipment, not just under it, so measure the full area.

Landscape and playground depths, and how rubber compares with wood loose-fill.

The 6-inch, 10-foot figure is the CPSC general guidance for shredded or recycled rubber. For a real playground, the surfacing must carry an ASTM F1292 certificate covering the equipment fall height; do not use marketing fall-height claims generically.

Playground Surfacing

Size the loose rubber for a play area at the depth its fall height requires.

Landscape Beds

Estimate rubber mulch for a long-lasting bed or border that will not decompose.

Play Sets at Home

Work out the rubber under a swing set or climber across the full use zone.

Pathways and Pet Areas

Figure rubber for a soft path or a pet run.

Comparing with Wood

See how rubber depth and cost compare with the wood mulch calculator.

1. Too Shallow for Safety

Under play equipment, rubber must be deep enough for the fall height, about 6 inches for 10 feet. A thin layer is not a safety surface.

2. Using Wood Depths for Rubber

Wood fill needs about 9 inches; rubber gets a 6-inch exception. Do not apply wood depths to rubber or the reverse.

3. Ignoring Compression

Loose fill settles about 25 percent. Install proud and top up to hold the rating.

4. Measuring Only Under the Equipment

The surface must cover the whole use zone around the play set, not just directly below it.

5. Trusting a Marketing Fall Height

Headline fall-height claims often mean bonded rubber, not loose mulch. Use the product ASTM F1292 certificate.

6. Assuming Every Bag Is the Same

Bags are 0.8 or 1.5 cubic feet by brand. Check the rating or the count is off.

The calculator estimates bags, volume and a rough weight from area and depth.

Multiply the area by the depth in inches, divide by 12 for cubic feet, then by the bag size for bags. A 200 sq ft bed at 2 in is 33.3 cubic feet, about 42 bags of 0.8 cubic feet.

About 6 inches of loose shredded rubber protects to a 10-foot fall height per CPSC guidance. Match the depth to your product ASTM F1292 certificate for the equipment.

A 0.8-cubic-foot bag covers about 4.8 square feet at 2 inches or 9.6 at 1 inch; a 1.5-cubic-foot bag covers about 3 square feet at 6 inches. Coverage is the bag size times 12, divided by the depth.

About 34 of the 0.8-cubic-foot bags or 18 of the 1.5-cubic-foot bags. A cubic yard is 27 cubic feet.

Rubber absorbs impact better per inch, so CPSC allows 6 inches of shredded or recycled rubber as the exception to the 9-inch loose-fill rule for most fall heights.

About 28 pounds per cubic foot, or roughly 0.38 tons per cubic yard. A 0.8-cubic-foot bag is about 24 pounds and a 1.5-cubic-foot bag about 40.

About 2 inches over landscape fabric. It does not decompose, so unlike wood it is not topped up each year.

Yes. Loose fill compresses about 25 percent over time, so a playground must be installed proud and topped up to keep its tested fall-height rating.

No. It estimates quantity. A public playground must use a surfacing product with an ASTM F1292 certificate covering the equipment fall height, per CPSC Pub. 325.

No. The calculator runs entirely in your browser and nothing is stored or sent.

• CPSC – Public Playground Safety Handbook (Pub. 325) (Loose-fill surfacing depth and critical fall height.)
• ASTM F1292 – Impact Attenuation of Playground Surfacing (Standard for tested critical fall height.)
• Inch Calculator – Mulch Calculator (Cubic-yard and coverage math.)