Mulch calculator
Enter the bed length, width and the depth you want to find out how many bags to buy.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter length, width, depth and bag size.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Volume (m³) = length × width × (depth in cm ÷ 100). Liters = volume × 1000. Bags = liters ÷ bag size, rounded up. 1 cubic yard = 0.764554857984 m³.
Example
Inputs: Length = 5 m, Width = 2 m, Depth = 7.5 cm, Bag size = 50 L. Result: Mulch volume: 0.75 m³; In liters: 750 L; Bags: 15.
Limits and caveats
- Mulch settles after spreading and watering; add about 10% if you want the full depth after it settles.
- Split irregular beds into rectangles and add the results.
Questions about this tool
How deep should mulch be?
Usually 5 to 10 cm. Thinner layers let weeds through, and much thicker layers can trap moisture around stems.
Does it work for decorative stone?
Yes for volume, but stone is usually sold by weight, so multiply the volume by the density your supplier gives.
How do I do a round bed?
Circle area = 3.1416 × radius². Enter that area as the length with a width of 1 m to get the same volume.