Soil and Topsoil Calculator

How much topsoil, compost or garden soil a bed, border or raised planter needs, in cubic yards, cubic metres or bags.

Units

Switching units keeps your measurements. Nothing is reset.

Areas

Depth

How deep the soil needs to be once it has settled.

How are you buying it?

How are you buying it?

Waste allowance

Waste allowance

10% allows for the settling that follows the first few waterings.

Offcuts, breakages, pattern matching and the occasional damaged piece all mean you use more material than the bare area. Keeping a few spare pieces for future repairs is also normal.

This is a planning allowance, not a rule. Adjust it for your layout, your material and your own tolerance for a second trip to the store.

Estimated cost

Cost uses the price you enter. This product never shows invented market prices.

Your result appears here

Enter your measurements to see how much material to buy.

How to use this calculator

  1. 1

    For a raised bed, measure the inside of the frame, not the outside, and use the depth you actually want filled rather than the height of the sides.

  2. 2

    For a border or lawn repair, measure the area and set the depth of the layer you are adding.

  3. 3

    Add an area for each bed. Several planters of the same size are quicker as one area with the combined footprint.

  4. 4

    Choose bulk for a delivered load, or bags and enter the volume printed on the bag.

A worked example

Two 8 ft × 4 ft raised beds filled to 10 in deep, with a 10% overage for settling:

  1. Add the sections together

    26.67 ft³ + 26.67 ft³53.33 ft³

  2. Add the overage

    53.33 ft³ × 1.158.67 ft³

  3. Convert to the unit you order in

    58.67 ft³2.17 yd³

  4. You will need

    2.17 yd³

This example is produced by running the calculator above, so it always matches what the tool does.

The formula

Volume is area × depth, with the overage applied on top. For bags, that volume is divided by the volume of one bag and rounded up. Soil is one of the materials where the overage matters most: loose soil compacts noticeably after the first few waterings.

Filling beds

Fill to below the rim

Filling a raised bed to the very top means soil washes over the edge every time it rains. An inch or two of freeboard is normal, so measure the depth you want filled rather than the height of the frame.

Topsoil, garden soil and compost are not the same

They are priced differently and behave differently. Many raised beds are filled with a blend rather than pure topsoil, so work out the total volume here and split it between products afterwards.

Expect it to settle

A freshly filled bed drops noticeably in the first season. Ordering slightly over is normal, and topping up later is easy.

Common questions

How much soil does a 4x8 raised bed need?
A 4 ft × 8 ft bed filled to 10 inches is 32 square feet × 0.833 feet, which is about 26.7 cubic feet, or just under one cubic yard. Enter your own dimensions above for the exact figure.
How many bags of soil are in a cubic yard?
A cubic yard is 27 cubic feet. Bagged soil is commonly sold in one, one and a half or two cubic foot bags, so a yard is somewhere between fourteen and twenty seven bags depending on the size.
Should I fill a raised bed entirely with topsoil?
Usually not. Most growers use a blend. This calculator gives you the total volume to fill; how you split that between topsoil, compost and other amendments is a gardening decision rather than a mathematical one.