Home & Construction

Mulch Calculator — Free 2026

Calculate how much mulch you need for garden beds and landscaping. Get results in cubic yards, cubic feet and number of bags.

Length (ft)

Width (ft)

Depth (inches)

—

Cubic Yards

—

Cubic Feet

—

Bags (2 cu ft)

How It Works

Enter bed dimensions
Set the depth
Read your results

How to Estimate Mulch for Garden Beds

Mulch is essential for healthy garden beds — it suppresses weeds, retains soil moisture, regulates temperature, and adds organic matter as it decomposes. Whether you are using bark chips, shredded hardwood, cocoa hulls, or rubber mulch, accurate volume estimation ensures you buy the right amount without multiple trips to the store or wasted material.

The Mulch Formula

The calculation is the same as any volume measurement: length times width times depth. Since beds are measured in feet but mulch depth is typically specified in inches, the depth must be converted to feet by dividing by 12. One cubic yard contains 27 cubic feet, and a standard bag of mulch holds 2 cubic feet. For measuring irregular bed shapes, break them into rectangles and triangles using our square footage calculator.

Recommended Mulch Depths

The ideal mulch depth depends on the material and purpose. Fine-textured mulches like shredded hardwood settle quickly and should be applied at 3-4 inches. Coarser materials like bark nuggets can be applied at 2-3 inches since they resist compaction. Around established trees, maintain 2-4 inches but pull mulch back from the trunk to prevent rot. Vegetable gardens benefit from 2-3 inches of straw or grass clippings.

Bulk vs. Bagged Mulch

Bagged mulch is convenient for small projects — each 2 cubic foot bag covers about 8 square feet at 3 inches deep. For larger landscapes, bulk delivery by the cubic yard is far more economical, typically costing 40-60% less per cubic yard. Most landscape suppliers offer free or low-cost delivery for orders of 2 yards or more. For related landscaping projects, try our gravel calculator to estimate materials for paths and borders.

Frequently Asked Questions

How do I calculate how much mulch I need?

Multiply the length by width of the area in feet to get square footage. Multiply by the desired depth in feet. This gives cubic feet. Divide by 27 for cubic yards. For 2 cubic foot bags, divide total cubic feet by 2.

How deep should mulch be?

Apply mulch 2-4 inches deep around plants, shrubs, and trees. A 3-inch depth is ideal for most applications. Never pile mulch more than 4 inches deep as it can prevent water from reaching roots. Keep mulch 2-3 inches away from plant stems and tree trunks.

How many bags of mulch are in a cubic yard?

One cubic yard equals 27 cubic feet. Standard mulch bags contain 2 cubic feet, so you need approximately 14 bags per cubic yard. Some bags hold 3 cubic feet, requiring only 9 bags per yard.

How often should I replace mulch?

Organic mulch decomposes and should be refreshed annually. Add 1-2 inches of new mulch each spring to maintain a 3-inch depth. Inorganic mulch like rubber or stone lasts much longer. Remove old mulch if the total depth exceeds 4 inches before adding new material.