Work out exactly how much topsoil you need for beds, borders and lawn prep. Enter your length and width (or the total area), pick a depth, and we calculate the volume in litres and cubic metres — then price up the cheapest way to buy it in bulk bags or handy bags.
As a rule of thumb you need 10 litres per square metre for every centimetre of depth. A standard bulk bag holds around 730 litres, so one bag covers roughly 7m² at 10cm deep.
01 — The Calculator
Pick a material, pace out your plot, and the value engine prices every way to fill it — hippo bags, dumpy bags or handy sacks.
10 cm
Depth changes the volume a lot — 5cm mulch is normal, raised veg beds want 20cm+.
Not sure? See the depth guide belowEnter dimensions to calculate.
Volume
0 litres
Cubic
0.00 m³
Area
0.0 m²
Est. weight
0.00 tonnes
Enter your plot dimensions and the value engine will price the cheapest way to cover it.
Worked example: raised veg beds
Two raised beds totalling 10m², filled to 20cm deep: 10m² × 20cm × 10 litres = 2,000 litres (2m³). That's 3 standard bulk bags of 730L, or 27 handy 75L bags — the calculator compares both and flags the cheaper option.
Allow 10 litres per m² for every 1cm of depth. So 10m² at 10cm deep needs 10 × 10 × 10 = 1,000 litres (1m³).
Garden Calculator — Project
My garden project · 20 September 2026
| Item | Qty | Each | Total |
|---|---|---|---|
| Estimated total | £0.00 | ||
Prices from the Garden Calculator sample trade catalogue — confirm with your merchant before ordering.