How to calculate how much mulch you need
Mulch is sold by volume: cubic yards in bulk, cubic feet in bags. So the job is to turn your beds into square feet, multiply by the depth, and convert. Here is the math the calculator runs, using the bed it opens with: a 20 x 4 ft border plus a 5 ft ring around a tree, 3 inches deep.
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1
Find the area of each bed
Rectangles are length times width: 20 × 4 = 80 sq ft. Circles are 3.14 times the radius squared: a 5 ft ring has a 2.5 ft radius, so 3.14 × 2.5 × 2.5 = 19.6 sq ft.
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2
Add the beds together
80 + 19.6 = 99.6 sq ft of bed to cover.
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3
Multiply by the depth in feet
3 inches is 0.25 ft, so 99.6 × 0.25 = 24.9 cubic feet.
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4
Convert to yards or bags
Divide by 27 for cubic yards: 24.9 ÷ 27 = 0.92 yd. Or divide by the bag size: 24.9 ÷ 2 = 12.5, so buy 13 bags of 2 cu ft.
A shortcut pros use: square feet × depth in inches ÷ 324 = cubic yards. The 324 is the number of square feet one yard covers at 1 inch deep.
How far does a yard of mulch go?
One cubic yard is 27 cubic feet: 13.5 bags of 2 cu ft or 9 bags of 3 cu ft.
| Depth | 1 cubic yard covers | One 2 cu ft bag covers |
|---|---|---|
| 1 inch | 324 sq ft | 24 sq ft |
| 2 inches | 162 sq ft | 12 sq ft |
| 3 inches | 108 sq ft | 8 sq ft |
| 4 inches | 81 sq ft | 6 sq ft |
Mulch for common bed sizes
Shredded hardwood, 3 inches deep. Tap a size to load it into the calculator.
| Bed area | Cubic yards | 2 cu ft bags |
|---|---|---|
| 50 sq ft | 0.46 | 7 |
| 100 sq ft | 0.93 | 13 |
| 200 sq ft | 1.85 | 25 |
| 300 sq ft | 2.78 | 38 |
| 500 sq ft | 4.63 | 63 |
| 1,000 sq ft | 9.26 | 125 |
How deep to spread each type
More is not better. A layer that is too thick keeps water and air from reaching the roots, and mulch piled against bark invites rot and rodents. Clemson Cooperative Extension suggests no more than 2 to 3 inches of fine wood or bark and up to 4 inches of coarse nuggets.
| Type | Depth | Bulk price per yard |
|---|---|---|
| Shredded hardwood | 2–3 in | $40–$70 |
| Cedar | 2–3 in | $100–$110 |
| Pine bark nuggets | 3–4 in | $30–$40 |
| Pine straw | 3 in settled | Sold by the bale |
| Rubber | 2–3 in | $80–$160 |
| Decorative stone | 2–3 in | $50–$180 |
Pine straw is fluffy when it comes off the bale and settles fast. Spread it 4 to 5 inches thick to end up with about 3 inches. UGA Extension figures one bale covers about 50 sq ft at a fresh 5-inch layer. Bale sizes vary a lot by region, so check the label.
Bulk or bags: what it really costs
Bagged mulch costs more per yard but has no delivery fee and fits in a car. Bulk is cheaper per yard, but most yards charge $50 to $150 to deliver. With hardwood at $45 a yard, $4.50 for a 2 cu ft bag and a $75 delivery fee, the break-even sits near 5 cubic yards, about 65 bags. Under that, bags win. Over it, bulk wins by more every yard, and a $50 delivery fee pulls the break-even down to about 3 yards. The calculator works this out with your own prices.
Bulk also means a pile on the driveway. Lay a tarp first, since dyed mulch can stain concrete, and plan to move it the same day if rain is coming. A wheelbarrow holds about 6 cubic feet, so a yard is four or five trips.
Hiring it out costs about $72 to $94 per cubic yard for wood mulch, delivered and spread, based on 2026 national averages from LawnStarter and LawnLove. Labor alone runs about $20 to $60 a yard. On a small job the crew minimum often sets the price.
Tips from the pros
- No mulch volcanoes. Pull mulch 2 to 3 inches back from shrub stems and tree trunks. Spread a flat ring, wider rather than deeper.
- Measure what is already there. Poke a finger in. If 1 inch of old mulch remains, you only need to add 2 inches, not 3. Set the depth to what you are adding.
- Keep it off the house. Clemson suggests leaving 6 to 12 inches between mulch and the foundation. Wood and rubber mulch can both burn, so keep them clear of siding, grills and where people smoke.
- Weed and water first. Mulch slows new weeds but won't kill the ones already growing. Pull them, water the bed, then mulch.
- Edge the bed. A clean 2 to 3 inch trench at the lawn edge keeps mulch in place and looks sharp.
- Odd shapes: break the bed into rectangles and circles, or measure the longest length and the average width and multiply. Enter the result as a free-form bed.
Common questions
How much area does a yard of mulch cover?
One cubic yard covers 324 square feet at 1 inch deep, 162 square feet at 2 inches, 108 square feet at 3 inches and 81 square feet at 4 inches.
How many bags of mulch are in a yard?
A cubic yard is 27 cubic feet, so it equals 13.5 bags of 2 cubic feet or 9 bags of 3 cubic feet. In practice, buy 14 of the 2 cubic foot bags.
How deep should mulch be?
Spread 2 to 3 inches of fine wood or bark mulch and up to 4 inches of coarse nuggets. Keep it a few inches away from stems and trunks, and never pile it up against a tree.
Is it cheaper to buy mulch in bags or in bulk?
Bulk mulch costs less per yard, but the delivery fee makes bags cheaper for small jobs. For basic hardwood, bulk usually starts to win somewhere between 3 and 6 cubic yards, depending on the delivery fee.
Should I remove old mulch before adding new mulch?
Usually not. Rake the old layer to loosen it and top it up to a total of 2 to 3 inches. Remove it only if it is moldy, matted, or already deeper than 3 to 4 inches.
Do I need landscape fabric under mulch?
Not for most planted beds. Wood mulch breaks down on top of the fabric and weeds root into it. Fabric makes more sense under stone or rubber, which do not break down.
Sources and assumptions
Prices are U.S. national averages checked in October 2026. Your local yard may be well above or below them, so every price in the calculator can be changed.
- Depths, distance from stems and walls, and landscape fabric: Clemson Cooperative Extension, Mulch (HGIC).
- Pine straw coverage (about 50 sq ft per bale at a 5-inch layer) and bark coverage: UGA Cooperative Extension, Managing a Water-Wise Landscape (C 895-4). We assume a bale covers about 50 sq ft of settled 3-inch layer, the conservative end.
- Bulk prices by type (hardwood $45, cedar $110, rubber $90 per yard), delivery $50–$100 and labor $20–$60 per yard: HomeAdvisor mulching cost guide, updated June 2026.
- Bag prices ($3.25–$6.50), bulk $30–$135 per yard, delivery $70–$140, installed $77–$94 per yard: LawnStarter mulch cost guide, October 2026.
- Installed $72–$87 per yard, truckloads of 10–15 yards, landscape fabric $0.12–$0.45 per sq ft: Lawn Love mulch cost guide, October 2026.
- Bags $2–$8, landscape fabric $0.05–$0.25 per sq ft, delivery $50–$150: HomeGuide mulch prices, 2026 edition.
- Stone ($50–$180) and rubber ($80–$160) mulch per yard, cedar and pine straw prices: Fixr mulching cost guide, August 2025. Decorative stone bags ($6–$8 for 0.5 cu ft): HomeGuide gravel prices.
- Assumptions: landscape fabric and pins at $0.20 per sq ft with 10% overlap; bulk orders rounded up to the next half yard with a 1-yard minimum; bags rounded up to whole bags. Default bag prices for cedar ($6.50), rubber ($7.50 for 0.8 cu ft) and pine straw ($6 per bale) are typical store prices and vary by region.