About this tool
This mulch calculator turns the size of your planting beds into a shopping quantity: cubic yards for a bulk delivery, the number of 2 cubic foot and 3 cubic foot bags, and the approximate weight of the load for the mulch type you choose. Add as many beds as you like as rectangles, circles, or a known area, set the depth you want (3 inches is the usual target for a new bed), and include a waste allowance for settling and uneven ground. If you enter bulk and bag prices the tool compares the cost of each option so you can see when a delivery beats hauling bags. It is meant for homeowners refreshing beds each spring, landscapers quoting jobs, and anyone deciding between a truckload and a cartload; a metric switch works in meters, centimeters, cubic meters, and liters.
How it works
Each bed's area is found from its shape (length x width, or pi x diameter² / 4 for a circle) and multiplied by how many beds of that size you have. Volume in cubic feet = total area in square feet x depth in inches / 12, then multiplied by 1 + waste%. Cubic yards = cubic feet / 27, which is the same as the landscaper's rule that one cubic yard covers 324 square feet at 1 inch deep (108 sq ft at 3 in). Bag counts are the cubic feet divided by the bag size, rounded up to whole bags; a bulk order is rounded up to the next half yard. Weight = cubic yards x the density of the mulch type, using typical dry weights per cubic yard (about 500 to 650 lb for bark and wood mulches, 250 lb for pine straw, 1,100 lb for compost, 1,300 lb for rubber). Metric mode converts meters and centimeters to feet and inches internally and reports cubic meters, liters, and kilograms.
Frequently asked questions
How deep should mulch be?
Two to three inches is right for most beds: enough to block light to weed seeds and slow evaporation, but thin enough that water and air still reach the soil. Coarse materials such as bark nuggets and wood chips can go to 4 inches; fine mulches such as shredded leaves or compost should stay at 2 inches or less because they mat down. Keep mulch a few inches away from tree trunks and plant stems, and when topping up an existing bed only add what is needed to bring the total back to 3 inches, often just 1 inch.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it equals 13.5 bags of 2 cu ft or 9 bags of 3 cu ft. In practice you buy whole bags, so 1 cubic yard means 14 of the 2 cu ft bags. Bulk mulch is usually cheaper per cubic yard than bagged once you need more than about 2 to 3 yards, but bags are easier to move, store, and spread a little at a time, and they come in more colors and types.
How much area does a cubic yard of mulch cover?
One cubic yard covers 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches, and 81 sq ft at 4 inches. Divide 324 by the depth in inches to get the coverage for any other depth. A 2 cu ft bag covers 12 sq ft at 2 inches or 8 sq ft at 3 inches, and a 3 cu ft bag covers 18 and 12 sq ft respectively.
How much does a cubic yard of mulch weigh?
Dry bark and wood mulches weigh roughly 500 to 650 lb per cubic yard; wet mulch can weigh 800 to 1,000 lb. Pine straw is much lighter at about 250 lb, compost is heavier at around 1,100 lb, and rubber mulch is about 1,300 lb per cubic yard. A standard half-ton pickup can safely carry about 1 to 1.5 cubic yards of dry wood mulch by weight, though the bed volume is usually the limit; the calculator shows the estimated weight for the type you pick.