Mulch Calculator
Stop guessing bags at the garden center. Get the volume, the bag count, and whether bulk delivery beats bags on price.
How it works
- Volume = length x width x depth
- Cubic yards = cubic feet / 27
- Bags = total cubic feet / bag size, rounded UP
- Both buying routes are costed so you can compare
Worked example
A 20 ft x 5 ft bed at 3 inches deep: 100 sq ft x 0.25 ft = 25 cu ft, which is 0.93 cubic yards. In 2 cu ft bags that is 13 bags (about $52 at $4 a bag). One bulk yard at $45 is cheaper here, and you avoid 13 trips with a wheelbarrow from the car.
Assumptions to know
- Depth is the settled depth - fluffy bagged mulch compacts down, so do not under-order for a fresh bed.
- Bulk yards are rounded up to the nearest quarter yard for ordering.
- Delivery fees for bulk material are not included.
Results are planning estimates only. Always check the coverage and instructions on the actual product you buy, and measure your own space carefully before ordering. When in doubt, a little extra material is cheaper than a second trip or a stalled job.
Frequently asked questions
How deep should mulch be?
2 to 3 inches is the usual range for garden beds. Go thinner (about 2 inches) around delicate plants and up to 4 inches where you are suppressing weeds in an open bed.
How many bags of mulch equal a cubic yard?
A cubic yard is 27 cubic feet, so it takes about 13.5 bags of 2 cu ft mulch (buy 14) to equal one yard. Above about 2 yards, bulk delivery is usually much cheaper.
Bags or bulk - which should I choose?
Bags win for small beds, tight access and clean storage. Bulk wins on price as soon as you need more than roughly 15 to 20 bags, if you have somewhere for the pile to sit.
Does this work for soil, gravel and stone too?
Yes - the volume math is identical for topsoil, compost, gravel and decorative stone. Just enter your area and depth, and use the bag size on the product you are buying.