A cubic yard of mulch covers about 100 to 110 square feet at a 3-inch depth
A cubic yard is a measurement of volume: 3 feet long, 3 feet wide, and 3 feet deep. When you spread mulch at the standard landscaping depth of 3 inches, one cubic yard covers roughly 100 to 110 square feet. If you spread it thinner (2 inches), it covers more area—around 150 to 165 square feet. If you go thicker (4 inches), it covers less—about 75 to 80 square feet.
The exact coverage depends on how densely you pack the mulch as you spread it and what type of mulch you use. Shredded hardwood mulch, for example, settles and compacts slightly differently than wood chips or bark nuggets. But for planning purposes, the 3-inch depth at 100 to 110 square feet is the standard assumption most landscapers and garden centers use.
Key Takeaways
- One cubic yard of mulch at 3 inches deep covers approximately 100 to 110 square feet.
- At 2 inches deep, one cubic yard covers 150 to 165 square feet; at 4 inches deep, it covers 75 to 80 square feet.
- To find how many cubic yards you need, measure your bed in square feet, decide your desired depth, and use a straightforward calculation or online calculator.
- Mulch settles over time, so ordering 10 to 15 percent extra accounts for settling and future top-ups.
How to calculate cubic yards for your garden bed
Start by measuring the length and width of the area you want to mulch, in feet. Multiply those two numbers to get square footage. Then decide what depth you want—3 inches is standard for weed suppression and moisture retention, but 2 inches works for established beds and 4 inches for new plantings or heavy-traffic areas.
Once you have your square footage and depth, divide the square footage by 100 (if using 3-inch depth). For example, a bed that is 20 feet long and 10 feet wide is 200 square feet. At 3 inches deep, you would need 200 ÷ 100 = 2 cubic yards. If you wanted 4 inches instead, divide by 75: 200 ÷ 75 = about 2.7 cubic yards.
Many garden centers and online mulch calculators let you enter your measurements directly and will do this math for you. Having your square footage written down before you call or visit saves time.
Why depth matters more than you might think
The difference between 2 inches and 4 inches of mulch is not just appearance—it affects how well mulch does its job. At 2 inches, mulch suppresses some weeds and retains some moisture, but it is thin enough that sunlight can still reach soil in spots, especially as it settles. At 3 inches, you get solid weed suppression and good moisture retention without looking overdone. At 4 inches or deeper, you risk trapping too much moisture against the soil, which can rot plant crowns and encourage fungal growth.
New beds or areas with heavy foot traffic often benefit from the thicker 4-inch layer because mulch compacts faster in those spots. Established perennial beds usually do fine at 2 to 3 inches. Around trees, keep mulch 3 to 4 inches away from the trunk to prevent rot and pest problems.
Mulch settles—order extra to account for it
Fresh mulch looks fluffy when it arrives. Over the first few months, it breaks down slightly and compacts under rain and foot traffic, losing 10 to 15 percent of its volume. If you measure carefully and order exactly what the calculator says, you may find your beds looking thinner than you expected by mid-summer.
A practical approach is to order 10 to 15 percent more than your calculation suggests. If you calculated 5 cubic yards, order 5.5 to 5.75 cubic yards. You can use the extra for top-ups later in the season or in other areas. Most garden centers will not penalize you for a small overage, and it is easier to use extra mulch than to place a second order.
Different mulch types and how they measure
Shredded hardwood mulch, wood chips, and bark nuggets all sell by the cubic yard, but they do not all weigh the same or compact the same way. Shredded hardwood is finer and denser, so it settles more noticeably and may cover slightly less area than the standard 100 to 110 square feet. Larger bark nuggets are fluffier and may cover a bit more area, but they also shift around more easily if you have foot traffic or water runoff.
When you order, ask the garden center what type of mulch they are selling and whether they have observed any differences in settling or coverage. Some centers mix their own blends, and a staff member who knows their product can give you a more accurate estimate for your specific situation.
Measuring irregular or curved beds
Not every garden bed is a perfect rectangle. For L-shaped beds, curved borders, or island plantings, break the area into simpler shapes. Measure the length and width of each rectangle or section, multiply to get square footage for each, then add them together. For a curved bed, you can estimate by measuring the longest length and average width, or sketch it on graph paper and count squares.
If your bed is very irregular, take a photo from above, print it on graph paper, and count the squares. This method is slower but more accurate than eyeballing. Once you have total square footage, use the same depth-based calculation as before.
Frequently Asked Questions
How much does a cubic yard of mulch weigh?
A cubic yard of mulch typically weighs 400 to 800 pounds, depending on the type and how wet it is. Shredded hardwood mulch is denser and heavier (600 to 800 pounds), while bark nuggets are lighter (400 to 500 pounds). Freshly delivered mulch that has been rained on will weigh more than dry mulch.
Can I use less than 3 inches of mulch?
Yes, 2 inches works for established beds where you are mainly topping up, but it is thinner than ideal for weed suppression. Anything less than 2 inches is usually too thin to be effective. If budget is tight, 2 inches is a reasonable compromise.
Should I remove old mulch before adding new mulch?
You do not have to remove old mulch completely, but if it is matted, moldy, or more than 4 inches deep already, rake it out or break it up. Fresh mulch mixed with old mulch settles unevenly. If the old layer is still in decent shape, you can add 1 to 2 inches of fresh mulch on top.
What if I order too much mulch?
Extra mulch keeps in a dry spot for months. You can use it for touch-ups as the season progresses, spread it in other garden areas, or offer it to a neighbor. Most garden centers do not take returns on bulk mulch, so ordering slightly extra is better than coming up short.
How long does mulch last before I need to replace it?
Mulch breaks down over time—typically lasting one to three years depending on the type and climate. Shredded hardwood breaks down faster (one to two years) because it is finer. Bark nuggets last longer (two to three years). You will know it is time to refresh when the layer looks thin or the mulch has turned dark and crumbly.