Mulch, Gravel and Topsoil Calculator
Enter the size and depth of the area to see how much mulch, gravel or soil to order.
- Volume needed
- —
- Volume needed, in cubic yards
- —
- Volume with waste
- —
- Bags needed
- —
Where to find your numbers
Not sure what to enter? Here is where to find each value for your own home. If you cannot find one, leave the example value and treat the result as a rough estimate.
Length and width
The size of the bed, path or area you want to cover.
- Measure in feet with a tape measure or a measuring wheel.
- For a curved bed, lay a garden hose where the edge will go, then measure the longest length and width and use the average width for a rough estimate. Or split it into rectangles.
- Subtract areas you will not cover, such as a tree trunk or a stepping stone, if they are large.
Depth (inches)
How deep you want the layer to be.
- Mulch in garden beds is commonly 2 to 3 inches deep. Keep it away from tree trunks and plant stems.
- Gravel paths and drives are often 2 to 4 inches or more, depending on use. Check the supplier's advice for the type of stone.
- For topsoil, a few inches is common for lawn repair and more for a new bed. Check what your plants need.
Extra for waste (%)
Extra for settling, uneven ground and spillage.
- About 10% is a reasonable allowance for most jobs.
- Use more if the ground is very uneven, and less if you are filling a neat, level container such as a raised bed.
Bag size (cubic feet)
The volume of one bag, if you are buying bags rather than a bulk delivery.
- It is printed on the bag, for example "2 cu ft". Bagged mulch is often 2 cubic feet, and topsoil bags are often smaller, around 0.75 to 1 cubic foot.
- For large areas, bulk delivery by the cubic yard is usually cheaper than bags. Look at the cubic yards result.
- Stone and gravel are often sold by the ton rather than the cubic yard. Roughly 1.3 to 1.5 tons make a cubic yard, but ask the supplier for the exact material.
How it works
Volume in cubic feet is length x width x depth in inches / 12. Cubic yards is cubic feet divided by 27. Waste is added as a percentage, and bags are the volume with waste divided by the bag size, rounded up. For a concrete slab, use theconcrete calculator.
Frequently asked questions
How much mulch do I need?
Multiply the length and width of the bed (in feet) by the depth (in feet, which is inches divided by 12) to get cubic feet. Divide by 27 for cubic yards. A 20 by 10 foot bed with 3 inches of mulch is 50 cubic feet, or about 1.85 cubic yards.
How deep should mulch, gravel or topsoil be?
Garden bed mulch is commonly spread 2 to 3 inches deep. Gravel paths and driveways are often 2 to 4 inches or more, depending on use. For topsoil, a few inches is common for lawn repair and more for new beds. Follow the guidance for your plants or project.
Cubic yards or tons?
Mulch and soil are usually sold by the cubic yard or in bags. Gravel and stone are often sold by the ton. Crushed stone and gravel weigh roughly 1.3 to 1.5 tons per cubic yard, but it varies, so ask the supplier for the weight of the exact material.
How big are the bags?
Bagged mulch commonly comes in 2 cubic foot bags. Topsoil and potting soil bags are often smaller, around 0.75 to 1 cubic foot. The size is printed on the bag, and bulk delivery is usually cheaper for large areas.
Something not working? Tell us
Related tools
How the numbers are produced: see our methodology.