Home / Mulch Calculator

Mulch Calculator

A mulch calculator tells you how much mulch a bed needs. It takes the bed size and the spread depth, and returns the volume in cubic yards and bags, plus the cost for bulk or bagged. Type your bed size below and set the depth. Everything runs in your browser, with no signup.

Updated for 2026

Your bed

Enter the bed size and depth. Results update instantly.
ft
ft
inches
$/ yd³
Mulch to order
0
Volume
0 ft³
Area covered
0 ft²
2 ft³ bags
0
Bulk cost
$0
Bagged cost (at $4 / bag)
$0

How much one cubic yard of mulch covers

A cubic yard is 27 cubic feet. The area it covers depends on the depth. Tap a row to set that depth.

DepthArea per cubic yardBags per yardUse

How the mulch volume is calculated

Mulch is sold by volume. Multiply the bed area by the depth, with the depth converted from inches to feet, then divide by 27 to get cubic yards:

Cubic yards = Area × ( Depth ÷ 12 ) ÷ 27

There are 27 cubic feet in a cubic yard, and a standard bag of mulch holds 2 cubic feet, so a cubic yard is about 13.5 bags. Bulk mulch delivered by the cubic yard is usually cheaper than bags once you need more than a handful, but bags are easier to handle for a small bed.

Worked example (Stand: 2026)
  • Bed20 ft × 10 ft
  • Area (20 × 10)200 ft²
  • Depth3 in (0.25 ft)
  • Volume (200 × 0.25)50 ft³
  • Cubic yards (50 ÷ 27)1.85 yd³
  • Bags (50 ÷ 2)25 bags
  • Bulk cost (1.85 × $35)$65
  • Bagged cost (25 × $4)$100

Frequently asked questions

How much mulch do I need?
Multiply the bed area by the depth in feet for cubic feet, then divide by 27 for cubic yards. The calculator above does this and also gives the bag count and a cost for bulk and bagged.
How much does a cubic yard of mulch cover?
About 324 square feet at 1 inch, 162 at 2 inches, 108 at 3 inches, and 81 at 4 inches deep. The reference table above lets you tap a depth to load it.
How many bags is a cubic yard?
About 13.5 of the standard 2 cubic foot bags. Bulk delivery by the yard usually wins on price once you need more than 6 to 8 bags.
How deep should mulch be?
Two to three inches for most beds. That holds moisture and suppresses weeds without smothering roots. Keep it back a couple of inches from stems and trunks.
Does this calculator store my numbers?
No. Everything is calculated in your browser. Nothing you enter is sent to a server or saved.

More free yard calculators

One job per tool, each on its own page, all free and browser based.