Mulch Calculator
✓ Your estimate
--
Cubic Yards
--
Cubic Feet
--
3 cu ft Bags
⚠ Over 3 cubic yards? Bulk delivery is almost always cheaper than bags. Call your local landscape supplier for pricing.
What the Result Means
Mulch is sold in bags (2 or 3 cubic feet each) at home improvement stores, or in cubic yards for bulk delivery. One cubic yard equals 27 cubic feet, or about 9 bags of 3 cu ft mulch.
Before mulching, if you are preparing a new bed with fresh soil, see the topsoil calculator. For new lawn areas adjacent to beds, the sod calculator estimates rolls and pallets. For gravel path alternatives or bed borders, the gravel calculator can help. All outdoor tools are listed at the outdoor calculators page.
Recommended Mulch Depths
| Depth | Best For |
|---|---|
| 2 inches | Annual refresh over existing mulch |
| 3 inches | Standard new bed -- best balance of weed control and air circulation |
| 4 inches | New beds with heavy weed pressure |
| 6 inches | Paths only -- not recommended around plants (can suffocate roots) |
Keep mulch 2-3 inches away from tree trunks and plant stems. Piling mulch against trunks traps moisture and causes rot.
How the Calculation Works
Cubic Feet = Length x Width x (Depth / 12)
Cubic Yards = Cubic Feet / 27
Bags = Cubic Feet / Bag Size (cu ft)
Worked Example
Example: 25 ft x 6 ft garden bed, 3 inches deep
1
Convert depth: 3 / 12 = 0.25 feet
2
Cubic feet: 25 x 6 x 0.25 = 37.5 cubic feet
3
Cubic yards: 37.5 / 27 = 1.39 cubic yards
4
3 cu ft bags: 37.5 / 3 = 13 bags (round up)
5
At 1.39 yards, compare bag vs. bulk pricing before ordering
Bags vs. Bulk Delivery
Assumptions Used by This Calculator
- Bed area is calculated from length x width in feet.
- Depth is entered in inches and divided by 12 to convert to feet.
- Volume is calculated as area x depth (in feet).
- Cubic feet are divided by 27 to get cubic yards.
- Bag counts are based on the selected bag size (2 or 3 cubic feet).
- Actual coverage can vary by mulch texture, moisture content, and settling over time.
Frequently Asked Questions
How deep should mulch be?
2 inches is right for refreshing existing mulch. 3 inches is standard for a new bed. 4 inches for heavy weed suppression. Do not exceed 4 inches around plants -- thick mulch can mat down and prevent water from reaching roots.
How many bags of mulch equal one cubic yard?
One cubic yard equals 27 cubic feet. A 3 cubic foot bag requires 9 bags per cubic yard. A 2 cubic foot bag requires about 14 bags per cubic yard. Use the calculator above for your exact area and depth.
Is bulk mulch cheaper than bags?
For anything over 2-3 cubic yards, bulk delivery is almost always cheaper. A cubic yard of bulk hardwood mulch typically costs $30-60 depending on your region. The equivalent in bags at retail prices is usually 2-3 times more expensive.
How much mulch do I need around trees?
Apply 3 inches of mulch in a ring around trees, keeping it 2-3 inches away from the trunk. Extend the ring as wide as the drip line (outer edge of canopy) if possible. Never pile mulch against the trunk -- this traps moisture, causes rot, and invites pests.
Can too much mulch hurt plants?
Yes. More than 4 inches of mulch can mat down and block water and air from reaching roots. Piling mulch against tree trunks (called volcano mulching) traps moisture, causes bark rot, and creates habitat for pests and disease.
Should I remove old mulch before adding new?
Not usually. If existing mulch is under 3 inches, top-dress with 1-2 inches of fresh mulch. If it is over 4 inches deep, rake out the old layer first -- excessive mulch depth blocks water and oxygen from reaching plant roots.
When is the best time to mulch?
Spring after soil warms and fall before frost are the best times. Spring mulching retains moisture and suppresses summer weeds. Fall mulching insulates roots from freeze-thaw cycles. Avoid mulching when soil is frozen or waterlogged.
Disclaimer: This calculator provides estimates only. Actual quantities depend on bed shape, existing mulch depth, and material density. Verify with your landscape supplier before ordering bulk delivery. See all outdoor material calculators.