Mulch is a beneficial addition in many garden settings. Accurately determining how much mulch to purchase to apply at an appropriate depth is important to be more efficient and save time and money.
Follow the steps below to calculate the amount of mulch needed.
Find the Area | Determine Mulch Depth | Calculate the Volume | More Information
Start by Finding the Area of the Planting Bed
To determine the amount of mulch needed for a particular area, it is necessary to know the area or square footage of the planting bed.
Use this article to learn how to calculate the area of your planting bed, regardless of its shape: How do I determine the size of my garden bed or lawn in square feet?
Websites and phone apps are also available to determine the area of your garden bed or yard using online maps. One example is this site: Measure My Lawn.
Determine Your Mulch Depth
Many hardwood chipped or shredded mulches are spread between 2 and 4 inches thick. Learn more about the best depth of mulch to use in this article: Using Mulch in the Garden.
Because you've most likely measured your area in square feet, you need to convert the depth from inches to feet. Use the table below to help determine the desired mulch depth in feet.
| Mulch Depth in Inches | Mulch Depth in Feet |
|---|---|
| 0.5 | 0.041 |
| 1 | 0.083 |
| 1.5 | 0.125 |
| 2 | 0.166 |
| 2.5 | 0.208 |
| 3 | 0.25 |
| 3.5 | 0.291 |
| 4 | 0.333 |
| 4.5 | 0.375 |
| 5 | 0.416 |
| 5.5 | 0.458 |
| 6 | 0.5 |
Determine the Amount of Mulch Needed
To determine the volume of mulch you need to purchase, multiply the area of the garden bed by the depth of mulch in feet.
Volume of Mulch = Area of Garden Bed × Height of Mulch (in feet)
For example, if you wish to freshen up the mulch layer on a 265 ft2 perennial garden bed with 1.5 inches of mulch, your calculation would look like this:
Volume of Mulch = 265 ft2 × 0.125 ft = 33.125 cubic feet
Convert to Cubic Yards
Mulch is commonly sold by the cubic yard - whether that be in bulk or in 1 or 2 cubic-yard bags. Once you've determined the amount of mulch needed in cubic feet, divide by 27 to get the amount in cubic yards. For example, for the garden bed mentioned above, your calculation would look like this:
Volume of Mulch = 33.125 ft3 / 27 ft3 = 1.22 cubic yards.
More Information
- Using Mulch in the Garden
- How to Determine Plant Quantity for Planting Beds
- Planting Trees in the Landscape
- Care of Newly-Planted Trees
- How to Plant Perennials
- How to Plant Bare Root Plants
- Tips for Shopping and Selecting Quality Plants
Photo credit: Ozgur Coskun/AdobeStock