Mulch is sold by the cubic yard, not by weight or bag count
A cubic yard is a block of material 3 feet wide, 3 feet deep, and 3 feet tall — 27 cubic feet total. Mulch suppliers measure in cubic yards because the volume stays the same whether the mulch is wet, dry, shredded fine, or chunky. You need to know the square footage of the area you want to cover and how deep you want the mulch, then convert that to cubic yards. Most landscape mulch goes down 2 to 4 inches deep.
One cubic yard covers roughly 324 square feet at 1 inch deep, 162 square feet at 2 inches deep, and 108 square feet at 3 inches deep. If you know your square footage and your target depth, you can find the cubic yards you need without a calculator by using the standard conversion table that suppliers and landscapers use.
Key Takeaways
- Measure the length and width of your mulch area in feet, then multiply them together to get square footage.
- Decide on your mulch depth — 2 to 3 inches is standard for most landscape beds, 4 inches for heavy-traffic areas.
- Use the conversion table: at 2 inches deep, divide your square footage by 162 to get cubic yards; at 3 inches deep, divide by 108.
- Round up to the nearest half yard when you order, because mulch settles and you may need extra for refilling later in the season.
- Mulch depth matters more than the total amount — too shallow and weeds push through; too deep and it can rot the base of plants.
Measure the area you want to cover in square feet
Start by measuring the length and width of the space in feet. Use a tape measure or a measuring wheel if the area is large. If your bed is rectangular, multiply length times width. If it is irregular — an L-shape, a curve, or multiple sections — break it into rectangles, measure each one, and add the totals together.
For example, a rectangular bed that is 10 feet long and 4 feet wide is 40 square feet. An L-shaped bed that is 10 feet by 4 feet on one arm and 6 feet by 3 feet on the other arm is 40 plus 18, or 58 square feet. Write down your total square footage before you move to the next step.
Decide on the depth you want
Mulch depth affects both how much you order and how well it works. A depth of 2 to 3 inches is standard for most flower beds and shrub borders — deep enough to suppress weeds and hold moisture, shallow enough that it does not pile against plant stems. Four inches is appropriate for areas with heavy foot traffic or where you want maximum weed suppression, but it can trap moisture against the base of trees and shrubs if you are not careful.
One inch is too shallow for most purposes; weeds will push through and the mulch will compact and wash away quickly. More than 4 inches can create a moisture barrier that prevents water from reaching the soil and can encourage rot at the base of woody plants. Stick to 2 to 3 inches for general landscaping.
Convert square footage and depth to cubic yards
Use this table to find how many cubic yards you need. Find your target depth in the left column, then divide your square footage by the number in the right column.
| Depth | Divide square footage by this number |
| 1 inch | 324 |
| 2 inches | 162 |
| 3 inches | 108 |
| 4 inches | 81 |
Example: You have a 200-square-foot bed and want 3 inches of mulch. Divide 200 by 108. The answer is 1.85 cubic yards. Round up to 2 cubic yards when you order.
If your area is smaller and the result is less than 1 cubic yard, you can buy mulch by the bag instead. A standard bag of mulch is 2 cubic feet. One cubic yard is 27 cubic feet, so you would need roughly 13 to 14 bags to equal 1 cubic yard. Bags are more expensive per cubic foot but work well for small areas or touch-ups.
Account for settling and future refilling
Mulch compacts and breaks down over time. In the first few weeks after you spread it, it will settle by 10 to 20 percent as it absorbs water and the pieces nestle together. By the end of the first season, you may lose another 10 to 15 percent to decomposition and washing. Order 10 to 15 percent extra to account for this settling, or round up to the nearest half yard.
Keep a note of how many cubic yards you ordered and how deep you spread it. The next year, when the mulch has thinned, you can order a top-up amount based on the same calculation. Many people find it easier to add 1 to 2 cubic yards each spring rather than replace the entire bed every few years.
Understand what cubic yard means when you order
When a supplier quotes you a price per cubic yard, they are selling you a volume, not a weight. Wet mulch weighs more than dry mulch, and shredded mulch compacts differently than chunky mulch, but the cubic yard stays the same. Some suppliers will deliver loose mulch in a truck; others will sell it bagged. Loose mulch is cheaper per cubic yard but requires you to have space to receive a delivery and a way to spread it. Bagged mulch costs more but is easier to handle and store.
Ask the supplier whether the quoted price includes delivery. Delivery charges often depend on distance and the size of the load. For small orders — 1 to 3 cubic yards — bagged mulch from a garden center may be cheaper than paying a delivery fee for loose mulch, even though the per-yard price is higher.
Double-check your math before you order
Ordering too little means a second trip and a second delivery fee. Ordering too much means paying for mulch you do not need and having to store it. Use the table above and write down each step: square footage, target depth, the divisor, and the result. If the math feels uncertain, call the supplier and read them your measurements — most will calculate the cubic yards for you over the phone.
If you are ordering for multiple beds, calculate each one separately and add the totals. A 100-square-foot bed at 3 inches (0.93 cubic yards) plus a 150-square-foot bed at 2 inches (0.93 cubic yards) is roughly 2 cubic yards total, not 1.86 — rounding up protects you against settling and measurement error.
Frequently Asked Questions
How much does a cubic yard of mulch weigh?
Mulch weight varies widely depending on moisture content and type. Dry mulch weighs 400 to 600 pounds per cubic yard; wet mulch can weigh 700 to 1,000 pounds. Suppliers usually do not quote by weight because the same cubic yard can vary so much. Stick to volume (cubic yards) when ordering.
Can I use the same calculation for wood chips or bark?
Yes. Wood chips, bark, and shredded mulch all use the same cubic yard measurement. The conversion table works for any loose landscape material sold by volume. Density varies slightly between types, but the difference is small enough that the standard table is accurate for ordering purposes.
What if my bed is circular or has curved edges?
Measure the longest point across the circle (the diameter) and the widest point perpendicular to it. Multiply those two numbers and divide by 4 to estimate the square footage. For curved beds, break them into sections — rectangles and partial circles — measure each, and add them up. Slight overestimation is normal and accounts for settling.
Should I measure mulch depth before or after I spread it?
Measure the depth you want to achieve, not the depth of mulch in the bag or pile. When you spread mulch, it fluffs up slightly, so 2 inches of settled mulch in a bed may have come from slightly less material in the bag. Order based on your target finished depth, and the settling will work in your favor.
How often do I need to add more mulch?
Most landscape mulch lasts one to two years before it breaks down enough to need topping up. Check the depth each spring — if it has dropped below 2 inches, add another 1 to 2 cubic yards per 100 square feet. You do not usually need to remove the old mulch; new mulch blends in as it settles.