How deep should a raised bed be?

200–300mm suits salads and shallow-rooted vegetables; 300–450mm is better for carrots, potatoes and deep-rooted crops. Two sleeper courses give you roughly 250mm — the height Paul builds most often for veg growing.

How many railway sleepers do I need per layer?

Sleepers are typically 2.4m long — a 2.4m × 1.2m bed needs 3 sleepers per layer (two full lengths, one cut in half for the ends). Standard 250mm-wide sleepers stack two courses for a 500mm bed, or lay them on edge for 250mm.

FREE Garden CalculatorGarden & Landscaping Project Planning Assistant

Raised Beds Calculator

Enter your raised bed measurements and get exact sleeper and soil quantities, costs and a ready-to-order material list.

Start here

01 — The Calculator

How much soil and materials does your raised bed need?

Pick a material, pace out your plot, and the value engine prices every way to fill it — hippo bags, dumpy bags or handy sacks.

Run length

0.0 m

Full sleepers

0 × 2.4m

Cheapest mix

0 pieces

Left over

0.0 m spare

Best price

—

Enter your plot size below — we'll price the cheapest way to cover it.

Sleeper run (m)

Standard UK sleepers are 2.4m long — we mix full and half (1.2m) sleepers for the cheapest fit. For raised beds, multiply the run by the number of courses high.

The Catalogue

Your Materials Catalogue

Browse and customise your personal price list below. The default prices shown are indicative — useful as a starting point for budgeting, but your actual merchant prices will vary.

Why set your own prices?

When you update a product with your negotiated merchant price, every estimate and project board you create will automatically use your rate. Your quotes reflect what you actually pay, not a generic average — giving you more accurate margins and faster, more professional estimates.

How it works

1Click “Customise your own prices” and find the product below
2Enter your merchant price
3Save — stored on this device, and synced to your trade account when logged in
4Every project board and trade estimate now applies your saved price automatically

Your custom prices can be updated at any time as your supplier rates change. Logged-in trade users: your prices follow you across every device.

Custom prices flow into the calculator, project board and trade estimates automatically.

Hard Landscaping4 products

2.4m Softwood Railway Sleeper (250 × 125mm)

Wooden Sleepers

2.4m Softwood Sleeper

Pressure-treated UC4 softwood sleeper for raised beds, lawn edging and low retaining. Covers 2.4m of run each.

£21.95

£9.15 / m

2.4m Solid Oak Railway Sleeper (250 × 150mm)

Wooden Sleepers

2.4m Oak Sleeper

Dense, long-life European oak sleeper — the premium choice for feature beds and steps. Covers 2.4m of run each.

£38.95

£16.23 / m

1.2m Softwood Railway Sleeper (250 × 125mm)

Wooden Sleepers

1.2m Half Sleeper

Half-length softwood sleeper — fills the odd end of a run without paying for a full 2.4m length.

£12.75

£10.63 / m

Wooden Sleepers

Tub of 50 Screws

250mm black-coated structural timber screws — two per sleeper joint, no pre-drilling needed.

£9.95

£9.95 each

Default prices are indicative only — confirm with your merchant before ordering.

Common questions

Multiply length × width × depth in metres to get the volume — a 2.4m × 1.2m bed at 300mm deep takes about 0.86m³ (roughly 1.2 tonnes) of soil. Fill with a mix of topsoil and compost rather than compost alone, and the calculator above sizes the bags for you.

Garden Calculator — Project

My garden project · 12 October 2026

Item	Qty	Each	Total
Estimated total			£0.00

Prices from the Garden Calculator sample trade catalogue — confirm with your merchant before ordering.