Mulch Calculator
How much mulch do you need? Enter your bed size and depth to get cubic yards, bags, and how far it will spread.
Enter a bulk price to estimate cost.
You need
0.93cu yd
- Cubic feet
- 25 cu ft
- Cubic yards
- 0.93 cu yd
- Bags (2 cu ft)
- 13 bags
- Weight
- ≈ 0.42 tons
Bulk is sold by the yard — order 1 cu yd to have enough.
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Who needs a mulch calculator
This tool is for anyone covering beds, borders, or tree rings with mulch: laying a fresh layer over bare soil to block weeds, topping up a bed that's thinned out over the season, or planning a new landscape install. Enter your bed size and target depth, and it converts that to cubic yards and bag counts, so you know how much to order or haul home before you start spreading.
How much mulch do I need?
The formula is area times depth, converted to cubic yards: (length ft × width ft × depth in inches ÷ 12) ÷ 27. The calculator runs this for you, but it's worth seeing worked out once so the numbers make sense.
Example: a 25 ft × 10 ft border (250 sq ft) at 3 inches deep. Convert depth to feet: 3 ÷ 12 = 0.25 ft. Volume: 250 × 0.25 = 62.5 cubic feet. Cubic yards: 62.5 ÷ 27 ≈ 2.3 yards. Round up when ordering — a little extra mulch is cheaper than a second trip.
Coverage by depth (per cubic yard)
A cubic yard is a fixed volume — 27 cubic feet — but how far it spreads depends on how deep you lay it. Divide 27 by the depth in feet: at 3 inches (0.25 ft), one yard covers 27 ÷ 0.25 = 108 sq ft. Go thinner and it stretches further; go deeper and it covers less ground.
Use this table to sanity-check the calculator's output or rough out how many yards to order for a given bed size, without doing the division by hand each time.
| Depth | Coverage (per 1 cu yd) |
|---|---|
| 1 inch | 324 sq ft |
| 2 inches | 162 sq ft |
| 3 inches | 108 sq ft |
| 4 inches | 81 sq ft |
| 6 inches | 54 sq ft |
Bottom line: 3 inches is the standard weed-suppressing depth, covering 108 sq ft per yard.
Bags per cubic yard
Mulch is almost always sold in 2-cubic-foot bags at home centers, which makes the conversion straightforward: a cubic yard is 27 cubic feet, so 27 ÷ 2 = 13.5 bags per yard. Round up to 14 bags to cover a full yard without coming up short.
For a small bed you might just grab bags, but once you're past a few yards, bulk delivery usually costs less per yard and saves the trips back and forth. Price both before you commit — bag prices and bulk delivery minimums vary by region and season.
| Cubic yards needed | Bags (2 cu ft each) |
|---|---|
| 1 yard | 14 bags |
| 2 yards | 27 bags |
| 3 yards | 41 bags |
| 5 yards | 68 bags |
Bottom line: about 14 standard 2-cu-ft bags make up one cubic yard of mulch.
Mulch depth guide by bed type
Depth isn't one-size-fits-all. New beds fighting weeds want a thicker layer than an established bed that just needs refreshing, and trees need a shallow ring pulled back from the trunk rather than a deep pile against the bark. Piling mulch high and tight against a trunk — a 'mulch volcano' — traps moisture against the bark, invites rot and pests, and can suffocate the roots just under the surface, which prefer air along with water.
As a general rule, stay in the 2–3 inch range for most planted beds and keep any mulch a few inches clear of stems and trunks.
| Bed type | Recommended depth | Notes |
|---|---|---|
| New bed (weed suppression) | 3 inches | Thicker layer blocks light to weed seeds |
| Established/maintenance bed | 2 inches | Top up yearly as old mulch breaks down |
| Around trees and shrubs | 2–3 inches | Keep mulch a few inches back from the trunk |
| Avoid | 4+ inches | Risks mulch volcano, root suffocation, rot |
Bottom line: 2–3 inches is the sweet spot — more isn't better and can harm roots.
Mulch types: wood chips vs. bark vs. straw
Wood chips are a byproduct of tree trimming and chipping — often cheaper or even free from local arborists — and tend to break down faster, adding organic matter as they decompose. Shredded and nugget bark mulches are sold bagged or bulk, hold color longer, and knit together better on slopes so they resist washing away. Straw is common in vegetable gardens and around new seedlings since it's lightweight, breaks down quickly, and won't compete with young roots the way a denser mulch can.
Which one to pick depends on the job more than a fixed rule: ornamental beds near the house often use bark for appearance, vegetable and annual beds often use straw or wood chips, and large or informal areas often use whatever wood chips are locally available.
How it's calculated
- 1
Measure your beds
Enter length and width in feet. Use a circle for round beds, or type the total area.
- 2
Pick a depth
3 inches suppresses weeds in new beds; 2 inches is a maintenance top-up. Presets are 2, 3, and 4 inches.
- 3
Get yards and bags
We show cubic yards and the number of standard 2-cubic-foot bags. One cubic yard covers about 108 sq ft at 3 inches.
Frequently asked questions
How many bags of mulch are in a yard?
A cubic yard is 27 cubic feet, so it equals about 13.5 standard 2-cubic-foot bags — round up to 14 bags per yard.
How deep should mulch be?
2–3 inches for most beds. Deeper than 4 inches can suffocate roots and cause 'mulch volcano' damage around trunks.
How much does a yard of mulch cover?
About 108 sq ft at 3 inches deep, or 162 sq ft at 2 inches. The calculator shows coverage for your chosen depth.