Mulch Calculator
Enter the length and width of the bed and the depth of mulch you want, and the calculator returns the volume in cubic feet, cubic yards and cubic meters, plus the number of bags for the bag size you choose. Switch between imperial and metric units.
Last updated November 4, 2026
Your choice; depth varies by material and plant
An assumption; set 0 to skip
Result
2.037 cubic yards, 28 bags
Order total, about 55 cubic feet or 1.557 cubic meters, in bags of 2 ft³.
| Amount | Cubic feet | Cubic yards | Cubic meters |
|---|---|---|---|
| Bed volume | 50 | 1.852 | 1.416 |
| Settling (10%) | 5 | 0.185 | 0.142 |
| Order total | 55 | 2.037 | 1.557 |
Volume = length × width × depth. The depth is your choice and the settling allowance is an assumption; bag sizes vary by brand, so check the label.
Show the work
Formula: volume = length x width x depth; total = volume x (1 + settling / 100); bags = total / bag size, rounded up
- Bed: 20 ft x 10 ft x 3 in = 1.416 m³ = 50 ft³.
- Settling: 50 x 10% = 5 ft³.
- Total: 50 + 5 = 55 ft³ = 2.037 yd³ (27 ft³ per yd³) = 1.557 m³.
- Bags: one 2 ft³ bag is 2 ft³, so 55 / 2 = 27.5, rounded up to 28.
Result: 2.037 cubic yards, 28 bags
How the amount of mulch is worked out
volume = length × width × depth
total = volume × (1 + settling ÷ 100)
bags = total ÷ bag size, rounded up
A mulched bed is a flat box, so its volume is its length times its width times its depth. A 20 ft by 10 ft bed covered 3 in deep is 20 × 10 × 3 ÷ 12 = 50 cubic feet.
Bulk mulch is usually sold by the cubic yard. One cubic yard is 3 ft by 3 ft by 3 ft, which is 27 cubic feet, or about 0.7646 cubic meters, so 50 cubic feet is 50 ÷ 27 = 1.852 cubic yards, or 1.416 cubic meters.
Bagged mulch is sold by volume per bag, in cubic feet or liters. Divide the total by the size of one bag and round up. With 2 cubic foot bags, 50 ÷ 2 = 25 bags. One cubic foot is 28.3168 liters.
The optional settling allowance adds a percentage on top. The default of 10 percent is an assumption you can change or set to zero, not a standard. At 10 percent the same bed needs 55 cubic feet, or 2.037 cubic yards, which is 28 bags of 2 cubic feet because 27.5 rounds up.
See how we calculate for the formulas, sources and review schedule behind every calculator.
Also useful alongside this calculator: Concrete Calculator and Square Footage Calculator.
Choosing a depth
Depth is your input, and it has a direct effect on the amount, because doubling it doubles the mulch. For the 20 ft by 10 ft bed, 2 inches needs 33.33 cubic feet (1.235 cubic yards), 3 inches needs 50 cubic feet (1.852 cubic yards) and 4 inches needs 66.67 cubic feet (2.469 cubic yards).
As a general rule of thumb, many gardeners spread a few inches, but the right depth varies by material and by the plants in the bed, and it is not a standard. Check the guidance for your mulch and plants.
Bag sizes and bulk orders
The bag list offers common sizes as examples: 1, 2 and 3 cubic feet, and 25, 50 and 75 liters. Brands differ, so read the label and use Custom to enter the exact volume, in cubic feet or liters.
Because bags are rounded up, a bed that needs 27.5 cubic feet buys 28 two-foot bags, which is 56 cubic feet of mulch for the job.
Settling and refreshing mulch
Loose mulch compacts and breaks down, and uneven ground uses more than a flat measurement suggests, so a small allowance avoids a short delivery. The percentage here is only an assumption about that effect, and you can enter your own.
For the stone or soil below, see the Gravel Calculator, and for the area of a curved bed use the Square Footage Calculator.
Metric and imperial units
Switching units converts the values already entered and rounds them to two decimals. In metric, a bed 4 m long and 2.5 m wide covered 7 cm deep is 4 × 2.5 × 0.07 = 0.7 cubic meters, which is 0.916 cubic yards, or 14 bags of 50 liters because 0.7 cubic meters is 700 liters.
How to use the Mulch Calculator
- Choose imperial (feet and inches) or metric (meters and centimeters).
- Enter the length and width of the bed and the depth of mulch.
- Set a settling allowance, 10 percent by default, or 0 to skip it.
- Pick a bag size, or Custom to enter your own.
- Read the volume and bag count, then use Copy, Print or Share.
Worked example
A 20 ft by 10 ft bed mulched 3 in deep is 200 sq ft × 0.25 ft = 50 cubic feet, which is 1.852 cubic yards or 1.416 cubic meters. With a 10 percent settling allowance the order is 55 cubic feet, or 2.037 cubic yards, and 28 bags of 2 cubic feet.
| Bed | Cubic feet | Cubic yards | Bags |
|---|---|---|---|
| 10 ft × 10 ft | 25 | 0.93 | 13 |
| 10 ft × 20 ft | 50 | 1.85 | 25 |
| 20 ft × 20 ft | 100 | 3.7 | 50 |
| 20 ft × 30 ft | 150 | 5.56 | 75 |
Frequently asked questions
How many bags of mulch do I need for a 10 by 10 foot bed?
At 3 inches deep the bed needs 25 cubic feet, which is 13 bags of 2 cubic feet with no allowance.
How many cubic feet are in a cubic yard of mulch?
There are 27 cubic feet in a cubic yard, because a cubic yard is 3 feet by 3 feet by 3 feet.
How deep should mulch be?
It varies by material and plant, so treat any common range as a rule of thumb, not a standard, and enter the depth you choose.
Should I buy mulch in bags or in bulk?
Compare the price per cubic yard of each option, since 1 cubic yard equals 27 cubic feet of bagged mulch.
Does this calculator estimate the weight of mulch?
No. Weight depends on the material and how wet it is, so it only gives volume and bag counts.