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plotandpatch.com
Garden & building materials

Know exactly how much you need.

Free calculators for soil, compost, gravel and aggregate — giving you the answer in the bags and tonnes your local supplier actually sells.

Your answer, instantly
302litres
7bags needed

A 120 × 80 × 30 cm raised bed, in 50-litre bags — with a settling allowance added.

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Work out your soil in seconds

Enter your bed size below — no sign-up, no waiting. Switch to your region for local bag sizes.

Soil & Compost Planner

Raised Bed Soil Calculator

Enter your bed size and we'll work out exactly how much soil to buy — in the bags your local supplier actually sells.

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30 cm
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bags needed
A planning guide, not a final quote. These figures are based on typical bag volumes and soil densities, which vary by brand, moisture, and region. Please cross-check the amount against your own measurements and your supplier's actual bag sizes before ordering — and round up rather than down.

Bag volumes and settling vary by supplier. Always confirm quantities locally before you buy.

Why Plot and Patch

Built to get the number right

01

The right figures

Different materials weigh different amounts, and bag sizes differ by country. Our tools account for both — so your tonnage and bag count are right for what you actually buy.

02

We explain, not just calculate

Every tool comes with a plain guide: the depth to use, the waste to allow, the mistakes to avoid — the context a number alone can't give.

03

Honest by default

These are planning guides, and we say so. We tell you to round up, to check bag sizes with your supplier, and where costs can be trimmed.