One cubic yard of mulch covers 324 square feet at 1 inch deep, 162 square feet at 2 inches deep, and 108 square feet at 3 inches deep
The coverage depends entirely on how thick you spread it. A cubic yard is a fixed volume — 27 cubic feet — but the area it covers changes based on depth. Most landscaping jobs use mulch between 2 and 3 inches deep, which means one cubic yard typically covers between 108 and 162 square feet. If you spread it thinner (1 inch), you get more coverage. If you go thicker (4 inches), you get less.
To find how much you need, measure the square footage of the area you want to mulch, then decide on your depth. Thinner mulch (1 to 2 inches) works for annual beds and areas that dry out quickly. Thicker mulch (3 to 4 inches) suppresses weeds better and retains moisture longer, but costs more and can smother shallow-rooted plants if piled against tree trunks.
Key Takeaways
- One cubic yard covers 324 square feet at 1 inch deep, 162 square feet at 2 inches, and 108 square feet at 3 inches.
- Most homeowners use 2 to 3 inches of depth, so plan for one cubic yard per 108 to 162 square feet.
- Measure your bed length and width in feet, multiply them together to get square footage, then divide by your chosen coverage number.
- Mulch settles and breaks down over time, so you may need to add more each year, especially in the first season.
How to calculate the cubic yards you need
Start by measuring the length and width of each bed in feet. Multiply length by width to get square footage. If your bed is irregular, break it into rectangles, calculate each one, and add them together.
Next, decide on depth. For weed suppression and moisture retention, use 3 inches. For lighter coverage or annual beds, use 2 inches. Once you have your total square footage and depth, use this table to find how many cubic yards to order:
| Depth | Coverage per cubic yard | Cubic yards needed for 100 sq ft | Cubic yards needed for 500 sq ft | Cubic yards needed for 1,000 sq ft |
|---|---|---|---|---|
| 1 inch | 324 sq ft | 0.3 | 1.5 | 3.1 |
| 2 inches | 162 sq ft | 0.6 | 3.1 | 6.2 |
| 3 inches | 108 sq ft | 0.9 | 4.6 | 9.3 |
| 4 inches | 81 sq ft | 1.2 | 6.2 | 12.3 |
Round up when you order. Mulch settles as it dries, and you will likely need a little extra to top up beds after the first few weeks. Most suppliers sell in half-cubic-yard increments, so ordering 4.6 cubic yards means buying 5 cubic yards.
Why depth matters more than you might think
Mulch at 1 inch deep looks thin and does little to stop weeds or hold moisture. Rain and sun break it down quickly, and you will see bare soil within weeks. It is the cheapest option upfront but requires frequent replacement.
At 2 inches, mulch begins to suppress weeds and reduce water loss. This is a practical middle ground for most homeowners — enough benefit to justify the cost, but not so thick that it risks damaging tree roots or creating a moisture trap. Two inches is also the depth most landscape professionals recommend for annual maintenance.
At 3 inches and deeper, mulch becomes very effective at blocking weeds and keeping soil cool and moist. The downside: it costs more, and if you pile it against tree trunks or shrub stems, it can rot the bark and encourage disease. Keep mulch 3 to 6 inches away from any trunk or stem.
Different mulch types cover the same area, but density varies
Whether you buy shredded hardwood, pine bark, cedar, or recycled wood chips, one cubic yard is still one cubic yard. The coverage math does not change. What does change is how long the mulch lasts and what it costs.
Hardwood mulch is denser and breaks down slowly, so it holds its depth longer. Pine bark is lighter and breaks down faster, meaning you may need to top it up sooner. Cedar and cypress are aromatic and resist decay, but cost more. Recycled wood chips are the cheapest option and cover the same area, though they break down quickly and may contain contaminants.
For coverage purposes, treat all mulch types the same. Order based on square footage and desired depth. Choose the type based on budget, longevity, and appearance.
Account for settling and annual top-ups
Fresh mulch looks full and fluffy. Within a few weeks, it settles as moisture evaporates and the material compacts. By the end of the first season, your 3-inch layer may look like 2 inches. This is normal and does not mean you ordered wrong.
Plan to add a 1 to 2 inch top-up layer each year, especially in the first two years. This keeps weed suppression strong and maintains the appearance. After that, many beds need only a 1-inch refresh annually. Over time, mulch breaks down into soil, which is actually beneficial — it improves soil structure and adds organic matter.
If you want to avoid annual top-ups, order extra mulch the first year and plan to refresh every 18 to 24 months instead. This costs more upfront but saves time and repeated trips to the supplier.
Common mistakes that waste mulch or money
The biggest mistake is piling mulch against tree trunks and shrub stems. This traps moisture, rots the bark, and invites disease and insects. Keep mulch 3 to 6 inches away from any woody stem. A tree surrounded by a mulch volcano is a tree in trouble.
The second mistake is spreading mulch too thin. One inch looks like something, but it does almost nothing for weed suppression or moisture. If budget is tight, mulch fewer beds at proper depth rather than spreading thin mulch everywhere.
The third mistake is not measuring carefully. Eyeballing a bed or rounding down on the order means you will run short. Measure twice, order with a small cushion, and you will have enough.
Frequently Asked Questions
How much does a cubic yard of mulch weigh?
Wet mulch weighs 400 to 600 pounds per cubic yard depending on type and moisture content. Dry mulch weighs 200 to 400 pounds. This matters if you are hauling it yourself or need to know if your truck can handle the load. Always ask the supplier for the weight before you pick it up.
Can I use less than 2 inches of mulch?
You can, but it will not suppress weeds effectively or retain much moisture. One inch is mostly decorative. If cost is the limiting factor, mulch a smaller area at proper depth rather than spreading thin mulch over a large area.
How long does mulch last before I need to replace it?
Hardwood mulch lasts 2 to 3 years before breaking down significantly. Pine bark and recycled chips last 1 to 2 years. Cedar and cypress last 3 to 5 years. Most homeowners add a 1 to 2 inch top-up layer annually rather than replacing all the mulch at once.
What if my bed is an odd shape?
Break it into rectangles or triangles, calculate the area of each section, and add them together. For a circular bed, measure the radius (distance from center to edge), multiply it by itself, then multiply by 3.14. This gives you the square footage.
Should I put landscape fabric under mulch?
Landscape fabric blocks weeds but also blocks water and air from reaching the soil. Most professionals skip it and rely on mulch depth alone. If you use fabric, choose a permeable type and do not bury it under mulch — it works better when mulch sits on top of it.