Free Mulch calculator

How to calculate mulch for beds

Add a rectangle or circle for each bed. Enter a circle’s diameter, or a rectangle’s length and width. Deduct any excluded area from its own section so adjacent beds are not counted twice.

Set the mulch depth, then enter the bag volume from the product label. The example bag volume is editable. Open Material settings & waste if you want to add a purchase allowance; this calculator initially uses zero allowance.

Compare bags with a bulk order

Net volume is covered area × depth. With US measurements, convert depth in inches to feet before multiplying. Divide cubic feet by 27 for cubic yards.

For a fictional 12 × 8 ft bed at 3 inches deep, net volume is 24 cubic feet. With no additional allowance, that is 12 bags labeled 2 cubic feet, or about 0.89 cubic yards in bulk. The bag count rounds up after any allowance is applied.

Match the quantity to your plan

Results show the net volume, purchase volume, bag quantity, and bulk alternative. They are alternative ways to buy the same planned coverage, not quantities to add together. Existing mulch, uneven depth, and excluded planting areas can change the amount needed. Choose the appropriate depth for the bed and confirm actual bag volume before buying. US and metric inputs are supported.