Mulch Calculator
- Updated
- Imperial and metric
- Free, no sign-up
Results
1.22 yd³ of Shredded hardwood mulch, 17 bags
Includes 10% extra. In-place volume without the extra: 1.11 yd³.
How to use the mulch calculator
- Measure each bed. Use rectangles for borders, circles for tree rings and triangles for corner beds, and add each with Add area.
- Choose the mulch type and enter the depth you want after spreading. Three inches is a good default for most beds.
- Keep the 10% extra for settling unless you are only topping up an existing layer.
- Pick the bag size you are comparing, or enter a bulk price per cubic yard to estimate the cost.
Mulch calculation formula
Bags = Cubic feet ÷ Bag size (ft³), rounded up
In metric: cubic meters = area (m²) × depth (cm) ÷ 100, and bags = liters ÷ bag size. For example, a 200 ft² bed at 3 inches deep is 50 ft³. With 10% extra that is 55 ft³, or 2.04 cubic yards: 28 bags of 2 ft³ or 19 bags of 3 ft³.
How much area does a yard of mulch cover?
| Depth | Area 1 cubic yard covers | Area one 2 ft³ bag covers |
|---|---|---|
| 1 in | 324 ft² | 24 ft² |
| 2 in | 162 ft² | 12 ft² |
| 3 in | 108 ft² | 8 ft² |
| 4 in | 81 ft² | 6 ft² |
| 6 in | 54 ft² | 4 ft² |
| Depth | Area 1 m³ covers |
|---|---|
| 2.5 cm | 40 m² |
| 5 cm | 20 m² |
| 7.5 cm | 13.3 m² |
| 10 cm | 10 m² |
One cubic yard is 27 cubic feet, so it equals about 14 bags of 2 ft³ (13.5 exactly) or 9 bags of 3 ft³.
How deep should mulch be?
- Garden beds and borders: 2 to 4 inches (5–10 cm). Three inches suppresses weeds and holds moisture without smothering roots.
- Topping up: an existing layer usually needs only 1 inch or so each year as it breaks down.
- Around trees and shrubs: spread a wide, even ring, but keep mulch a few inches away from trunks and stems. Mulch piled against bark holds moisture against it and can lead to rot.
- Paths and play areas: wood chips are used deeper on paths. Play areas need much deeper loose-fill surfacing; follow the playground safety guidance for your country.
Bags or bulk?
Bagged mulch is convenient for a few beds and easy to carry. For anything over a cubic yard or two, bulk mulch from a landscape yard is usually much cheaper per cubic yard, though there may be a delivery charge or minimum order. Compare the two by entering a price per bag and a price per cubic yard in the calculator.
Tips for mulching
- Weed first. Pull or kill weeds before spreading, and water dry soil, so the mulch locks moisture in rather than out.
- Edge the beds. A clean edge keeps mulch from washing onto lawns and paths.
- Choose the right material. Shredded hardwood knits together and stays put on slopes; pine bark nuggets are light and can float away in heavy rain; wood chips suit paths.
- Weights vary. Mulch is sold by volume, and its weight changes a lot with moisture, so the weight shown is only a rough guide for trailer loads.
Frequently asked questions
How much mulch do I need?
Multiply the bed area by the depth to get the volume. A 100 sq ft bed at 3 inches deep needs 25 cubic feet, about 0.93 cubic yards, before allowing extra for settling. The calculator adds 10% by default.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it takes 13.5 bags of 2 cubic feet (buy 14) or 9 bags of 3 cubic feet. In metric, a cubic meter is 1,000 liters: 20 bags of 50 liters.
How much area does a yard of mulch cover?
One cubic yard covers about 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches and 81 sq ft at 4 inches.
How deep should mulch be?
Two to four inches (5–10 cm) is typical for garden beds, and 3 inches is a good default. Keep mulch a few inches away from tree trunks and plant stems, and top up an existing layer by about an inch a year.
How much does a yard of mulch weigh?
It varies a lot with the material and how wet it is, roughly 400 to 800 lb (0.2 to 0.4 tons) per cubic yard for common wood mulches. Mulch is sold by volume, so use the weight only as a rough guide for trailer loads.