🌿Mulch Calculator
Calculate how many cubic yards and bags of mulch you need for a garden bed or landscape area
Last updated: October 20, 2026
How to Use the Mulch Calculator
How to calculate how much mulch you need
- Measure the area. Measure the length and width of your bed in feet or meters. For a round or odd-shaped bed, split it into rectangles, calculate each one, and add the cubic yards together.
- Choose the depth. Two to three inches is right for most garden beds. Go thicker around trees but never pile mulch against the trunk.
- Add a margin (optional). An extra 5 to 10% covers uneven ground and settling.
- Read the results. You will see the total in cubic yards, cubic feet and cubic meters, and how many 2 and 3 cubic foot bags it equals.
- Estimate the cost (optional). Open Advanced options and enter the bulk price per cubic yard.
For several beds, calculate each one and add the cubic yards together.
Formula & Methodology
Mulch volume formula
Cubic yards = Length (ft) × Width (ft) × Depth (ft) ÷ 27
Because mulch depth is usually measured in inches, divide it by 12 first:
Cubic yards = Length × Width × (Depth in inches ÷ 12) ÷ 27
Worked example
A bed is 20 ft long, 10 ft wide, and you want 3 inches of mulch.
- Depth in feet: 3 ÷ 12 = 0.25 ft
- Volume: 20 × 10 × 0.25 = 50 cubic feet
- Cubic yards: 50 ÷ 27 = 1.85 cubic yards
- Bags: 50 ÷ 2 = 25 bags (2 cu ft each) or 50 ÷ 3 = 17 bags (3 cu ft each)
Rules of thumb
- 1 cubic yard covers about 100 square feet at 3 inches deep, or 160 sq ft at 2 inches deep.
- 1 cubic yard = 27 cubic feet, which is about 13 bags of 2 cu ft or 9 bags of 3 cu ft.
- Add 5 to 10% to cover uneven ground and settling.
Metric
In meters: m³ = Length (m) × Width (m) × Depth (cm) ÷ 100, and 1 m³ = 1.308 cubic yards.
About Mulch Calculator
Our mulch calculator is a free, easy-to-use tool designed to help youcalculate how many cubic yards and bags of mulch you need for a garden bed or landscape area. For professionals or those who need quick calculations, our calculator provides accurate results instantly.
Frequently Asked Questions
How do I calculate how much mulch I need?
Multiply the length by the width of the area in feet, multiply by the depth in feet (inches divided by 12), then divide by 27 to get cubic yards. A 20 ft by 10 ft bed at 3 inches deep needs 20 × 10 × 0.25 ÷ 27 = 1.85 cubic yards.
How much area does 1 cubic yard of mulch cover?
One cubic yard covers roughly 100 square feet at a depth of 3 inches, 160 square feet at 2 inches, or 324 square feet at 1 inch. The exact coverage depends on how loosely the mulch is packed.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it equals about 13.5 bags of 2 cubic foot mulch or 9 bags of 3 cubic foot mulch. Buying in bulk is usually cheaper than bags once you need more than about 2 cubic yards.
How deep should mulch be?
Aim for 2 to 3 inches in flower and shrub beds. Thinner layers do not suppress weeds well; layers over 4 inches can stop water and air reaching roots. Around trees, keep mulch a few inches away from the trunk to avoid rot and pests.
How do I measure a circular or irregular bed?
Split the bed into rectangles, calculate each one, and add the cubic yards together. For a circle, you can use a square with a side equal to 0.89 × the diameter, which has the same area. Rounding up slightly is better than running short.
How much mulch do I need for a 10x10 area?
A 10 ft by 10 ft area is 100 square feet. At 3 inches deep that is 25 cubic feet, or about 0.93 cubic yards, which is roughly 13 bags of 2 cubic foot mulch.
Should I order extra mulch?
Yes. Mulch settles after it is spread and beds are rarely perfectly level, so adding 5 to 10% avoids a second trip. Use the extra waste field above to include it in the total.
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