Mulch calculator for Illinois
Figure yard or bag quantities for each landscape bed, with mulch-depth advice for plant health.
Enter your project dimensions
One cubic yard holds 27 cubic feet, the same volume as exactly 13.5 bags sized at 2 cubic feet from a garden center. That conversion handles most of the calculation here. Put in your bed dimensions and chosen depth to see cubic yards for a bulk purchase and the matching bag count, making the store comparison straightforward. Shredded hardwood is light at around 600 lb per yard, so mulch is purchased by volume, and bulk delivery is never based on weight.
Calculate mulch for landscape beds
- Find the square footage of every bed in feet, then combine the totals. For circular beds, enter the diameter using the circle setting.
- Use 2 inches to renew an old mulch layer, or 3 inches on bare and newly made beds. More than 4 inches can keep roots from getting air.
- Use the result in both formats: bulk cubic yards, or 13.5 bags per yard for a store-bag comparison.
Bags (2 cu ft) = cubic yards × 13.5
Coverage by depth
| Depth | 1 cubic yard covers | 10 bags (2 cu ft) cover |
|---|---|---|
| 1 inch | 324 sq ft | 240 sq ft |
| 2 inches | 162 sq ft | 120 sq ft |
| 3 inches | 108 sq ft | 80 sq ft |
| 4 inches | 81 sq ft | 60 sq ft |
Common order sizes
| Project | Typical size | Depth | Cubic yards | ≈ Bags |
|---|---|---|---|---|
| Foundation beds along the house | 40 x 3 ft | 3" | 1.1 yd³ | 15 bags |
| Four tree rings | 4 ft across each | 3" | 0.5 yd³ | 6 bags |
| All beds, average yard | ≈ 500 sq ft | 3" | 4.6 yd³ | 63 bags |
| Annual refresh of the same beds | ≈ 500 sq ft | 1.5" | 2.3 yd³ | 31 bags |
| Playground surface | 15 x 15 ft | 6" | 4.2 yd³ | 56 bags |
Bulk versus bags: cost comparison
At Ten bags, the choice starts to change. Bags work well below that amount, but bulk is usually less expensive above it, and free delivery means there is no need to rent a truck. After bringing home 15 bags, many people find that a delivered yard, a tarp for what remains, and the job finished makes more sense.
Mulch depths for plant health
- After loosening last year's mulch with a rake, apply 2 inches over it.
- Put down 3 inches over exposed soil. That layer limits weed sprouting and helps the ground retain moisture through July.
- Leave a mulch-free ring 3-6 inches around tree trunks. Bark can rot and rodents can move in when mulch touches it. Keep the mulch shaped like a flat donut, not a volcano.
- Keep mulch at 4 inches or less in all areas. A saturated, overly deep layer cuts off air around roots.
- For playground areas, install playground-certified chip instead of landscape shred, keeping the surface at least 6 inches deep.
Pick the mulch type
The calculator is set for shredded hardwood. Its fibers lock together, helping it remain on mild slopes. Chips and nuggets may last one or two seasons beyond that, but hard rain can send them floating and spreading out. Dyed mulch breaks down more slowly while retaining its color. Each type uses the same volume calculation, so material type changes the appearance and refresh schedule, not the amount ordered.
On delivery day
Three yards of mulch makes a pile roughly the size of a small car. Set aside a parking spot on the driveway and place a tarp before it is dropped, since shredded mulch can discolor fresh concrete. Get it spread within a week or two. If a large pile sits for a month, heat can build inside and turn it sour. Plan on 30 to 45 minutes of wheelbarrow work for each yard, and save the final half-yard for the beds behind the garage that get missed.
Common mulch calculation questions
How many mulch bags equal a cubic yard?
How many cubic feet make up a yard of mulch?
How much mulch is needed?
What area will one yard of mulch cover?
What is the weight of a yard of mulch?
What does a yard of mulch cost?
Will mulch attract termites?
Can new mulch go over old mulch?
Other calculators
Avoid the 27-bag cart.
Shredded hardwood mulch sold by the yard with free driveway delivery.
