How much mulch do I need? Enter your bed dimensions and depth to get instant cubic yards, bag counts, and cost estimates for any mulch type.
10% typical for coverage and irregular shapes
Ready to calculate
Enter your area dimensions
Last updated March 31, 2026 by our expert review team
$37.5/yd³
2-3" deep • Natural, decomposes slowly
$47.5/yd³
2-3" deep • Insect-resistant, aromatic
$42.5/yd³
2-3" deep • Long-lasting, attractive
$100/yd³
1-2" deep • Permanent, no decay
$42.5/yd³
2-3" deep • Red/Black/Brown colors
Ruth Wairimu
Landscape Architect
Landscape architect with 9+ years of experience, AAK member, IFLA climate activist, and founder of Bloomwell.
See full profileHawkin
Certified Cost & Estimating Professional
AACE-certified estimator working with 20+ insulation companies including the two largest franchises in America.
See full profileUpdated March 2026
How we verify our calculatorsAverage bulk delivery prices. Bagged mulch typically costs 2-3x more per cubic yard.
Apply 2-3 inches for best weed control and moisture retention. Deeper than 4 inches suffocates roots and breeds fungal disease.
Keep a 3-6 inch gap between mulch and tree trunks or stems. Piling mulch against bark causes rot and root girdling.
Mulch in spring after soil warms to 60F. Mulching too early traps cold soil and delays plant growth.
Cedar and cypress naturally repel termites and ants. Avoid hardwood mulch within 3 feet of foundations in termite-prone regions.
Buy bulk for anything over 3 cubic yards. Bulk runs $30-55/yard delivered vs. $54-81/yard at bag prices.
Rubber mulch never needs replacement, but surface temps reach 160F in direct sun. For playground options, try our rubber mulch calculator. Never use it around edible plants.
For natural ground cover that's 40% cheaper per square foot, consider pine straw as an alternative to traditional mulch.
Planning a new lawn? Use our sod calculator to estimate pallets and costs for sod installation.
Building raised beds? Our raised bed soil calculator estimates soil mix, bags, and bulk delivery for any bed size.
Need soil under your mulch? Our soil calculator estimates topsoil, garden soil, and compost in cubic yards, tons, and bags.
The calculator measures your bed area (rectangular or circular), multiplies by your chosen depth, and converts to cubic yards, the unit most landscape suppliers price by. The waste factor isn't just about spillage: flower beds with shrubs and perennials have 15-30% of their area taken up by plant crowns that don't need mulch directly on top but do need coverage around them. We also factor in the slope of your beds. Mulch on even a gentle slope washes thinner at the top and piles up at the bottom, so you need more material to maintain even coverage. The cost comparison between bulk and bags helps you decide whether a delivery truck or a stack of bags from the garden center makes more financial sense for your project size.
Formula
Rectangular: Length × Width × (Depth ÷ 12) = Cubic Feet
Circular: π × Radius² × (Depth ÷ 12) = Cubic Feet
Cubic Feet ÷ 27 × (1 + Waste %) = Cubic Yards needed
How much mulch do I need?
Multiply length x width x depth (in inches), divide by 12 for cubic feet, then by 27 for cubic yards. Add 10% for irregular shapes.
How many bags of mulch in a yard?
One cubic yard = 27 cubic feet. Standard bags are 2 cu ft, so 14 bags per yard. Bags cost 50-70% more than bulk.
How deep should mulch be?
2-3 inches for organic mulches (hardwood, cedar, pine bark). The Arbor Day Foundation recommends no deeper than 4 inches to avoid trapping moisture and preventing rain from reaching roots.
Bulk or bagged, which is cheaper?
Bulk is cheaper: $30-55/yard vs. $54-81 at bag prices. Break-even is around 3 cubic yards after delivery fees.
How often should I replace mulch?
Hardwood and pine bark need annual top-up. Cedar lasts 2-3 years. Rubber mulch is essentially permanent.
Is cocoa mulch safe for dogs?
No. It contains theobromine, the same toxin in chocolate. Use cedar, pine bark, or rubber mulch if you have pets.
What type of mulch is best?
Hardwood ($30-45/yard) is the best all-rounder. Cedar adds insect resistance. Pine bark suits acid-loving plants. Rubber is ideal for playgrounds.
Does mulch attract termites?
Mulch doesn't attract termites but creates moisture they prefer. Keep wood mulch 6+ inches from foundations.
| Depth | Coverage per Cubic Yard | Bags per 100 sq ft | Best For |
|---|---|---|---|
| 1" | 324 sq ft | 2-3 | Light refresh over existing mulch |
| 2" | 162 sq ft | 4-5 | Standard flower beds and gardens |
| 3" | 108 sq ft | 6-7 | Weed control and moisture retention |
| 4" | 81 sq ft | 9-10 | Heavy weed areas and tree rings |
| Type | Price/Yard | Lasts | Annual Cost | Watch Out For |
|---|---|---|---|---|
| Hardwood | $30-45 | 1 year | $30-45/yr | Attracts artillery fungus near light-colored siding |
| Cedar | $40-55 | 2-3 years | $18-28/yr | Strong scent when fresh, fades in 2-3 weeks |
| Pine Bark | $35-50 | 1-2 years | $25-50/yr | Floats in heavy rain, avoid on slopes or near downspouts |
| Dyed (red/black) | $35-50 | 1-2 years | $25-50/yr | Color bleeds onto concrete in first rain, keep off walkways |
| Rubber | $80-120 | 10+ years | $8-12/yr | Gets scorching hot in sun (160°F+); not for edible gardens |
Annual cost calculated for a 10×20 bed at 3" depth (~1.85 cubic yards). Cedar and rubber have higher upfront costs but lower long-term expense because they last multiple seasons.
Hardwood mulch is the go-to here. Bulk delivery saves $40-60 over bags, but only if a dump truck can reach your beds.
Keep mulch 6 inches from the trunk. Cedar repels ants and beetles that colonize around tree bases. Rake old mulch before adding fresh.
Rubber mulch is the standard for playgrounds. It stays in place and provides fall protection. ASTM F1292 recommends 4 inches minimum for equipment under 7 feet.
The 'mulch volcano' around trees
Pull mulch back 3-6 inches from trunks. Piling it against bark traps moisture and invites rot and rodent damage.
Applying too deep
More than 4 inches creates a water-repelling mat. Roots grow into the mulch instead of soil. Stick to 2-3 inches.
Using the wrong mulch for the spot
Pine bark floats (bad for slopes). Cocoa mulch is toxic to dogs. Dyed mulch bleeds onto concrete. Match type to conditions.
Mulching over old mulch without checking depth
Rake existing mulch first and measure depth. Only add enough to bring total back to 2-3 inches.
Important Disclaimer
These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.