Gardens & grounds / Mulch
Work out how much mulch you need
Enter the garden bed area and spread depth. Compare bulk volume with the number of bags.
Describe the job instead
Material quantity
How much mulch?
Enter area square metres.
How it works
Put in your numbers
Use your own rates, times and measurements.
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It works it out as you type.
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Send it on, or keep it with the job.
What it covers: Find the bulk volume or bag count for a garden bed and spread depth.
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How to work out how much mulch you need
To work out mulch, you need the area of the garden bed and the depth you plan to spread. Multiplying them gives the volume, which you can buy in bulk or turn into a number of bags. Add a little extra for uneven beds and for settling.
- Choose metres or feet and enter the total bed area in square metres or square feet. Split odd shapes into rectangles and triangles and add them together. For a single rectangle, Work out the area multiplies length by width for you.
- Decide the spread depth for your material and change the starting depth to match. Use the guidance from your supplier, as it varies with the type of mulch and what you want it to do.
- Enter the depth in millimetres, or in inches if you chose feet. The calculator multiplies it by the area to give the base volume in cubic metres or cubic yards.
- Add an extra allowance as a percentage if the bed is uneven or the material settles after spreading.
- Read the bulk volume and the number of whole bags. Enter the bag size printed on the bag, in litres or cubic feet, and add a price per bag or a bulk price if you want the cost of each option.
Tips and common mistakes
- Enter the depth in millimetres, or inches if you work in feet. If you measured in centimetres, multiply by 10 first.
- Check the bag size on the label. Bags are sold in different volumes, often in litres or cubic feet.
- Keep mulch clear of plant stems and tree trunks to help prevent rot.
- Compare bulk and bagged prices. Bulk is often better value for big beds, while bags are easier for small areas or tight access.
Questions
How much mulch do I need for my garden?
Multiply the bed area by the depth you want to spread to get the volume, then add a little extra for uneven ground. For example, 10 m² at 0.05 m deep needs 0.5 m³ before any allowance. Order that volume in bulk or divide by the bag size for a bag count.
How many bags of mulch do I need?
Work out the volume from the bed area and spread depth, then divide by the volume printed on one bag. Make sure both are in the same unit, such as litres or cubic feet. Round up to the next whole bag.
How deep should mulch be?
It depends on the material and its purpose, such as weed control or keeping moisture in. Coarser materials are often spread thicker than fine ones. Follow the advice from your supplier or on the bag for the product you buy.
How many litres are in a cubic metre?
There are 1,000 litres in one cubic metre. So if you need 0.5 m³ of mulch, that is 500 litres, which you can divide by the bag size in litres.
Should I buy mulch in bulk or in bags?
Bulk usually suits large beds and is delivered loose, so you need space to tip it. Bags suit smaller areas, tight access or jobs spread over time. Compare the cost per unit of volume to see which is better value.
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