How Much Soil Do I Need? (Planters & Raised Beds Explained)

One of the most common questions gardeners ask is:
“How much soil do I actually need?”

Whether you’re filling a wooden planter, a raised bed, or a garden container,
getting the amount right saves money and avoids wasted compost.

### The simple way to calculate soil volume

To calculate how much soil you need, you’ll need three measurements:
- Length
- Width
- Depth

Measure the *internal* dimensions of your planter or raised bed.
Multiply these numbers together and divide by 1,000 to convert the total into litres.

If you’re working in inches, you’ll need to convert them to centimetres first.
This is where most people get stuck.

### Use our free soil volume calculator

To make it easy, we’ve built a free tool that does the maths for you:

👉 **Use our soil volume calculator**

It instantly shows:
- Total soil volume in litres
- The number of standard 40L compost bags you’ll need
- Support for both centimetres and inches

### How much extra soil should I allow?

It’s a good idea to allow a little extra soil for:
- Drainage layers
- Liners
- Settling after watering

Rounding up to the nearest full bag is usually the safest option.

### Choosing the right planter

If you’re looking for a long-lasting option, wooden planters are ideal for
both small gardens and larger outdoor spaces.

You can browse our range of handcrafted planters here:
👉Our Planters

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Using the right amount of soil helps plants establish properly and keeps
your garden looking its best.

Frequently Asked Questions

How much soil do I need for a planter?
Measure the internal length, width, and depth of your planter. Multiply these together and divide by 1,000 to get the volume in litres.

How many bags of compost do I need?
Divide the total soil volume in litres by 40 and round up to the nearest full bag.