MEASURE ONCE. BUY WITH CONFIDENCE.

Raised-bed soil calculator

A new raised bed or a top-up for an old one. Work out your soil order and compare bags with bulk.

01

Your spaces

Measurements

After changing units, use this button before editing dimensions. Enter only the dimensions for your selected shape.Convert units

Sample measurements are filled in to get you started. Replace them with yours.

Area 1

Area name

Shape

Length (ft)Width (ft)

Target depth (in)Already there (in)

We calculate only the depth you still need to add.

02

Your buying options

Prices optional

Use prices from your shop or supplier. Leave prices blank for a quantity-only plan.

Extra material (%)An adjustable allowance, not a compaction factor.Currency

Bagged material

Volume per bag (ft³)Price per bag

Bulk delivery

Price per yd³Delivery feeOrder increment (yd³)Ask whether your supplier rounds to ¼, ½, or whole units.

Working out your order…

No account or saved database record. Shared links include your entered measurements and prices.

TRY THE NUMBERS

Example: top up an existing raised bed

A raised bed measures 2 × 1 m inside. Your chosen fill depth is 30 cm and the existing soil is 20 cm deep.
2 × 1 × ((30 − 20) ÷ 100) = 0.2 cubic metres, or 200 litres. This example uses no extra allowance.
With 40-litre bags, 200 ÷ 40 = 5 bags. A bulk supplier selling in 0.1 cubic metre steps would supply 0.2 cubic metres.

Use your intended soil level as the target depth. Space left below the rim is not soil to buy; settling and your chosen allowance are separate decisions.

Open this example in the calculator

Opening the example loads these sample values in place of your current entries.

How to measure

Measure inside the boards, not around their outside edges. A is the 2 m inside length and B is the 1 m inside width. In the side view, 20 cm of soil is already present and 10 cm is added to reach 30 cm.Illustration only; not drawn to scale.

THE MATH, MADE SIMPLE

How this soil calculator works

We add the volume of every area, subtract the depth of material already there, then add your chosen allowance. Bags round up to whole bags. Bulk rounds up to the order increment you choose.

Rectangle: length × width × added depth.
Circle: π × (diameter ÷ 2)² × added depth.

For imperial measurements, cubic feet ÷ 27 gives cubic yards. For metric measurements, centimetres ÷ 100 gives depth in metres; one cubic metre equals 1,000 litres.

Before you order

Use your supplier’s bag volume and minimum order increment. Prices use your selected currency without exchange conversion. Both options should use the same tax basis.

Bag costs exclude any bag delivery fee. Add that separately if needed. Choose comparable materials when comparing prices.

Read the bags vs bulk guide ↗

Measure the space you’re actually filling

Use the inside dimensions of your raised bed. Subtract existing soil depth or any space intentionally left at the top. This tool estimates volume; it does not prescribe a soil mix or planting depth.