How much mulch do I need?
Enter the area of your beds, the depth of mulch and the mulch type. See how many cubic yards or bags to buy, what it weighs, and what it costs.
- Mulch to order
- 1.02 yd³
100 ft² at 3 in deep needs 1.02 yd³ of mulch, waste included.
- Cubic feet
- 27.5 ft³
- Cubic metres
- 0.78 m³
- 2 cu ft bags
- 14
- 3 cu ft bags
- 10
- 60 L bags
- 13
- Area covered
- 100 ft²
- Weight
- 0.34 tons
- Weight (metric)
- 0.31 t
Mulch to order: 1.02 yd³. 100 ft² at 3 in deep needs 1.02 yd³ of mulch, waste included.
How to calculate
Computes the mulch for an area at a chosen depth, with a waste allowance, in cubic yards, cubic feet, cubic metres and bags, and its weight and cost.
Example with the default inputs (Area Total area, Total area 100 ft², Depth 3 in, Mulch type Wood chips, Waste and settling 10%, Price is Per cubic yard): 100 ft² at 3 in deep needs 1.02 yd³ of mulch, waste included.
Method: volume = area × depth × (1 + waste ÷ 100); weight = volume × density; bags = volume ÷ bag size, rounded up
- The waste allowance is added to the volume before the bags, weight and cost are worked out.
- Bags are counted whole: 2 cu ft and 3 cu ft bags, and 60 L bags when the price is per 60 L bag.
- The typical densities are loose, dry bulk densities: wood chips 25 lb/ft³, bark 15, ground rubber 37.5 and gravel 105. Wet mulch weighs more. Pine straw and compost have no published value, so type one to see a weight.
- Weight is in US short tons of 2,000 lb.
Worked examples
Each example is checked against the calculator on every build.
- Area Total area, Total area 100 ft², Depth 3 in, Mulch type Wood chips, Waste and settling 10%, Price is Per cubic yard gives Cubic feet 27.5 ft³, 2 cu ft bags 14, 3 cu ft bags 10, Weight 0.34 tons.Source: Engineering ToolBox, Densities of common Products (woodchips 20 to 30 lb/ft³, bark 10 to 20 lb/ft³, ground rubber 25 to 50 lb/ft³). https://www.engineeringtoolbox.com/density-materials-d_1652.html
- Area Length × width, Length 20 ft, Width 5 ft, Depth 3 in, Mulch type Wood chips, Waste and settling 10%, Price $4.00, Price is Per 2 cu ft bag gives Cubic feet 27.5 ft³, Estimated cost $56.00.Source: Engineering ToolBox, Densities of common Products (woodchips 20 to 30 lb/ft³, bark 10 to 20 lb/ft³, ground rubber 25 to 50 lb/ft³). https://www.engineeringtoolbox.com/density-materials-d_1652.html
- Area Total area, Total area 500 ft², Depth 2 in, Mulch type Bark mulch, Waste and settling 0%, Price $35.00, Price is Per cubic yard gives Mulch to order 3.09 yd³, Estimated cost $108.02, Weight 0.63 tons.Source: Engineering ToolBox, Densities of common Products (woodchips 20 to 30 lb/ft³, bark 10 to 20 lb/ft³, ground rubber 25 to 50 lb/ft³). https://www.engineeringtoolbox.com/density-materials-d_1652.html
- Area Total area, Total area 107.6 ft², Depth 1.969 in, Mulch type Pine straw, Waste and settling 0%, Price is Per 60 L bag, Price $6.00 gives Cubic metres 0.5 m³, 60 L bags 9, Estimated cost $54.00.Source: Engineering ToolBox, Densities of common Products (woodchips 20 to 30 lb/ft³, bark 10 to 20 lb/ft³, ground rubber 25 to 50 lb/ft³). https://www.engineeringtoolbox.com/density-materials-d_1652.html
How it works
- Area = the total area you enter, or length × width.
- Volume to order = area × depth × (1 + waste ÷ 100). The waste allowance covers spills and settling.
- Cubic yards = cubic feet ÷ 27. Cubic metres use 1 ft = 0.3048 m exactly.
- Bags = volume ÷ bag size, rounded up to a whole bag, and at least 1 bag: 2 cu ft bags, 3 cu ft bags, or 60 L bags (0.06 m³).
- Weight = volume to order × density, in US short tons of 2,000 lb and in metric tonnes of 1,000 kg. The calculator uses the typical density of the mulch type unless you type your own.
- Cost = the volume in the price unit × the price. If the price is per bag, the calculator counts whole bags.
Typical densities
These are loose, dry bulk densities. Wet mulch weighs more, so a weight from the supplier is better when you have one.
| Mulch | Density used | Published value |
|---|---|---|
| Wood chips | 25 lb/ft³ | woodchips, 20 to 30 lb/ft³ |
| Bark mulch | 15 lb/ft³ | bark, wood refuse, 10 to 20 lb/ft³ |
| Rubber mulch | 37.5 lb/ft³ | ground rubber, 25 to 50 lb/ft³ |
| Stone mulch | 105 lb/ft³ | gravel, dry, 105 lb/ft³ |
| Pine straw, compost | none | no published value: type a density to see a weight |
Each density used is the middle of the published range. Sources: Engineering ToolBox, Densities of common Products and Dirt and Mud - Densities (retrieved September 27, 2026). Weight is shown in US short tons of 2,000 lb.
Worked examples by hand
100 sq ft of wood chips, 3 in deep, with 10% extra. 3 in = 0.25 ft. 100 × 0.25 × 1.1 = 27.5 ft³, which is 27.5 ÷ 27 = 1.02 yd³. That is 27.5 ÷ 2 = 13.75, so 14 bags of 2 cu ft, or 27.5 ÷ 3 = 9.17, so 10 bags of 3 cu ft. At 25 lb/ft³ it weighs 27.5 × 25 = 687.5 lb (0.34 tons).
A 20 ft × 5 ft bed, the same depth, at $4 a 2 cu ft bag. 20 × 5 = 100 sq ft, so again 27.5 ft³ and 14 bags. 14 × $4 = $56.
500 sq ft of bark, 2 in deep, no extra, at $35 a cubic yard. 500 × 2/12 = 83.33 ft³ = 3.086 yd³. The cost is 3.086 × $35 = $108.02, and the weight is 83.33 × 15 = 1,250 lb.
10 m² of pine straw, 5 cm deep, at $6 a 60 L bag. 10 × 0.05 = 0.5 m³ = 500 L. 500 ÷ 60 = 8.33, so 9 bags, and 9 × $6 = $54.
Other questions people ask
How much mulch do I need?
The amount of mulch needed depends on the area to be covered and the desired depth. Generally, a 2-4 inch layer provides good coverage. Multiply the area by the depth, add an allowance for waste and settling, and divide by 27 to get cubic yards. For example, 100 sq ft at 3 inches with 10% extra is 100 × 0.25 × 1.1 = 27.5 cubic feet, or 1.02 cubic yards.
What are the benefits of mulch?
Mulch helps regulate soil temperature, retain moisture, prevent weed growth, reduce soil erosion, and improve soil health. It also enhances the visual appeal of your landscape.
What types of mulch are available?
Common mulch types include wood chips, bark mulch, pine straw, rubber mulch, stone mulch, and compost. Each type has different properties, costs, and maintenance requirements.
How deep should I apply mulch?
For most applications, apply mulch 2-4 inches deep. Too little mulch won't provide adequate benefits, while too much can prevent water from reaching plant roots.
How many bags of mulch make 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.
How often should I replace mulch?
Organic mulches typically need replacement every 1-3 years as they decompose. Synthetic mulches like rubber can last 10+ years. Monitor your mulch and replace when it becomes thin or decomposed.
Can I use mulch around trees and shrubs?
Yes, but keep mulch 2-3 inches away from tree trunks and shrub stems to prevent rot and pest issues. Apply mulch in a donut shape around the base of plants.