Number Mulch Calculator
Mulch math without the parking-lot guesswork. Enter your bed area and how deep you want it, and get cubic yards for a bulk delivery and the bag count for the hardware-store run — with both costs, because the cheaper route flips with the size of the job.
Depth guide: 2 in to refresh existing mulch, 3 in for a standard new bed, 4 in where weeds are winning. If you fill in the bed length and width, they replace the area figure.
How it works
Volume = area × depth, with depth in feet: that gives cubic feet, and dividing by 27 gives cubic yards — the bulk-delivery unit. The standard mulch bag holds 2 cubic feet, so bags = cubic feet ÷ 2, rounded up. One cubic yard equals 13.5 bags, which is the conversion behind every bulk-vs-bagged price comparison.
Formula & worked example
Formula: Volume = bed area × depth, with depth converted to feet. Cubic yards = cubic feet ÷ 27; bags = cubic feet ÷ 2, because the standard mulch bag holds 2 cu ft. One cubic yard is 13.5 bags.
Worked example: Beds totaling 200 sq ft at 3 in deep need 50 cu ft of mulch: 1.85 cubic yards, or 25 bags. At $3.50 a bag that is $87.50; bulk at $35 a yard runs about $64.81 before delivery.
When to use this
- Spring cleanup has turned into four beds of different sizes and one decision: pallet of bags or a bulk drop on the driveway.
- You mulched last year, the beds look thin, and you need a refresh quantity rather than a new-bed quantity.
- A landscaper quoted a yardage figure and you want to check it against your own bed measurements.
- You are mulching around a new planting and need enough depth to matter without burying the crowns.
How to use it, step by step
- Add up your bed areas and enter the total square footage, or use the bed length and width fields for a single bed.
- Set the depth for the job in front of you: a refresh is not a new bed.
- Enter the bulk price per cubic yard and the price of a 2 cu ft bag locally.
- Read the cubic yards and the bag count side by side.
- Let the two cost lines — not habit — decide how this load arrives.
What the inputs mean
| Input | What it is | Typical values |
|---|---|---|
| Total bed area | Combined area of the beds being mulched, in square feet | 200 sq ft is the page default; add beds together |
| Bed length and width | Optional single-bed measurement that replaces the area figure | Use it when there is only one bed to do |
| Depth | How thick the mulch layer goes down, in inches | 2 in to refresh, 3 in standard new bed, 4 in where weeds are winning |
| Bulk price | Price per cubic yard, before delivery | $35 is the page default |
| Bag price | Price per standard 2 cu ft bag | $3.50 is the page default |
Another worked example
Beds totalling 320 sq ft, mulched 4 inches deep over bare, weedy ground: the volume is 106.67 cubic feet, which is 3.95 cubic yards. Bought in 2 cu ft bags that is 54 bags. Bulk at $38 a yard comes to $150.12, while the bags at $4.25 each total $229.50 — at this size the bulk load wins on price even before you count 54 trips from the car.
Frequently asked questions
How much mulch for 200 sq ft at 3 inches deep?
200 sq ft × 3 in is 50 cubic feet: 1.85 cubic yards, or 25 bags of 2 cu ft. At $3.50 a bag that is $87.50; a bulk yard-and-a-bit at $35 a yard runs about $65 plus delivery — close enough that convenience decides on a job this size.
How many bags of mulch in a cubic yard?
Thirteen and a half 2 cu ft bags make 27 cubic feet, so 14 bags to be safe. If the bag is 1.5 cu ft (some brands), it is 18 bags per yard — check the bag size printed on the front before comparing prices.
How deep should mulch be?
Two to three inches for most beds: enough to hold moisture and suppress weeds, not so much that water cannot reach the soil. Four inches only for new beds over bare, weedy ground. Never pile it against tree trunks — the "mulch volcano" rots bark.
Bulk or bags — which is cheaper?
Bags usually win under about a cubic yard (no delivery fee, no driveway pile); bulk wins beyond that, often by half. The calculator prices both on your exact volume so you can see where your job lands.
🪨 Stone instead of bark?
The Gravel Calculator adds the weight — tons — that mulch never makes you think about.
How do I add up several beds of different sizes?
Measure each bed's length and width, multiply for its area, and add the areas into one total for the area field — the calculator only needs the combined square footage and one depth. If your beds need different depths, run each depth group as its own calculation and add the yards, since a 2-inch refresh bed and a 4-inch new bed are different volumes wearing the same area.
Why does a fresh bed look thin again by autumn?
Mulch settles under rain and decomposes from the bottom up — that breakdown is the material doing its soil job, not a short delivery. A bed spread at 3 inches in spring is typically closer to 2 by autumn, which is why a light 2-inch refresh most years keeps the depth steady instead of a heavy layer all at once.