One cubic yard of mulch equals 13.5 standard bags
A standard bag of mulch holds about 2 cubic feet. Since one cubic yard contains 27 cubic feet, you need 13.5 bags to fill a yard. Most people buy 14 bags to account for settling and uneven ground.
The exact number can shift based on bag size. Some retailers sell 3 cubic foot bags, which would require 9 bags per yard. Always check the label on the bag itself — the cubic footage is printed on the front or back.
Mulch settles over time as it breaks down and compacts. Plan to add more in spring and fall to maintain depth. A 2-inch layer (the standard for weed control and moisture retention) will compress to about 1.5 inches within a few months.
Key Takeaways
- Standard 2 cubic foot bags require 13.5 to 14 bags per cubic yard of mulch.
- Larger 3 cubic foot bags require only 9 bags per cubic yard, so always verify the bag size before buying.
- Mulch settles and compacts as it ages, so you will need to refresh beds annually to maintain the original depth.
- Calculating by square footage and desired depth is more practical than buying by the yard if you have a small or oddly shaped bed.
How to calculate bags for your specific bed size
If you know the square footage of your bed and the depth you want, you can skip the cubic yard math. Measure the length and width of the bed in feet, multiply them together, then use this table to find how many bags you need.
| Bed Size | Bags for 2 inches deep (2 cu ft bags) | Bags for 3 inches deep (2 cu ft bags) |
|---|---|---|
| 50 square feet | 3 bags | 5 bags |
| 100 square feet | 6 bags | 9 bags |
| 150 square feet | 9 bags | 14 bags |
| 200 square feet | 12 bags | 18 bags |
| 300 square feet | 18 bags | 27 bags |
Two inches is the minimum depth for weed suppression. Three inches provides better moisture retention and looks fuller, but requires more material and costs more. For shrub beds, 2 inches is usually enough. For vegetable gardens or newly planted areas, 3 inches works better.
Why bag size matters when you shop
Retailers do not standardize bag sizes. Home Depot and Lowe's typically sell 2 cubic foot bags, but some stores carry 1.5 cubic foot or 3 cubic foot versions. Landscape supply yards often sell larger bags or bulk mulch by the yard, which is cheaper per cubic foot but requires a truck or delivery.
Bagged mulch costs more per cubic foot than bulk, but you pay only for what you use and avoid delivery fees for small projects. For beds under 200 square feet, bags are usually the better choice. For larger areas, bulk mulch becomes more economical.
Check the weight before you buy. A 2 cubic foot bag of wet mulch can weigh 30 to 40 pounds. If you are spreading it yourself, buying a few extra bags and spreading over two days is easier than trying to finish in one afternoon.
Accounting for settling and annual refresh
Mulch breaks down as it ages. Organic mulches like hardwood and cedar decompose faster than inorganic options like rubber. Within the first year, a 3-inch layer will compress to about 2 inches. By year two, it may be down to 1.5 inches.
Plan to add a 1-inch refresh layer each spring. This means buying about 6 to 7 bags per 100 square feet annually to maintain the original depth. Refreshing is cheaper than replacing the entire bed and keeps weeds from returning.
If you live in a wet climate, mulch breaks down faster. In dry climates, it lasts longer. Mulch in full sun breaks down quicker than mulch in shade because heat and UV light accelerate decomposition.
Bulk mulch versus bagged: when to choose each
Bulk mulch from a landscape supplier costs $25 to $50 per cubic yard, depending on type and location. A cubic yard covers about 150 square feet at 2 inches deep. Delivery usually runs $50 to $100, so bulk makes sense for projects over 300 square feet.
Bagged mulch at a home improvement store costs $3 to $6 per bag, or roughly $40 to $80 per cubic yard before tax. You avoid delivery fees and can buy only what you need, making bags the better choice for small projects or if you do not have a truck.
Some landscape suppliers will let you load your own truck for a lower price than delivery. If you have access to a pickup truck and live near a supplier, this is often the cheapest option for medium-sized projects.
Common mulch types and their coverage
Hardwood mulch is the most common bagged option. It breaks down moderately fast and works well for shrub beds and general landscaping. Cedar mulch costs more but lasts longer and smells better. Rubber mulch does not break down and lasts for years, but it does not improve soil as it ages.
Cypress and pine mulches are regional options that vary in price and availability. Dyed mulch (usually black or red) lasts longer than natural mulch because the dye slows decomposition, but it costs more upfront. All mulches cover the same area per cubic foot, so the choice is about durability, appearance, and budget.
Shredded bark mulch is lighter and easier to spread than chips, but it breaks down faster. If you are new to mulching, hardwood chips are the safest choice — they are affordable, widely available, and perform well in most situations.
Frequently Asked Questions
How many bags of mulch do I need for 100 square feet?
For a 2-inch depth, you need about 6 bags of standard 2 cubic foot mulch. For 3 inches, buy 9 bags. The exact number depends on the bag size listed on the package, so always check the label before calculating.
Is it cheaper to buy mulch in bags or bulk?
Bulk is cheaper per cubic foot, but delivery fees make it uneconomical for small projects. For areas under 200 square feet, bags are usually cheaper overall. For larger areas, bulk mulch becomes more economical even with delivery.
How long does bagged mulch last before it needs replacing?
Organic mulches like hardwood break down within one to two years. You do not need to replace the entire bed — just add a 1-inch refresh layer each spring. Rubber and dyed mulches last longer, sometimes three to five years, before needing a refresh.
Can I use less mulch if I put down landscape fabric first?
Landscape fabric blocks weeds but does not reduce how much mulch you need for appearance and moisture retention. You can use the same depth with or without fabric. Fabric does slow decomposition slightly, so mulch may last a few months longer.
What if I buy too many bags of mulch?
Unopened bags of mulch store well in a dry location for several months. You can use extra bags for refreshing beds next spring or in other areas of your yard. Opened mulch that has been exposed to rain may start to break down or mold, so store it under a tarp if you plan to keep it long-term.