Decide bed width
Keep width ≤ ~1.2 m so you can reach the centre without stepping in.
Raised Bed Calculator
Plan one bed or a whole kitchen-garden layout. Enter dimensions and bed count for total soil volume and practical build tips.
Calculator
Tap a screen and type with the keypad (or your keyboard), choose an option, then press =. The answer shows on the calculator screen, with full details underneath.
Garden Plant Finder
RAISED BED · GPF
How to measure
Follow these steps for accurate inputs and better results.
Set height for crops
30 cm suits many vegetables; deeper helps root crops and accessibility.
Multiply by bed count
Identical beds make ordering soil simple — use the count field.
Plan paths
Leave 40–60 cm paths for wheelbarrows and comfortable access.
Why this matters
Raised beds warm earlier, drain better on heavy soil, and reduce bending — if you fill them correctly.
Soil is the biggest cost after timber. Accurate volumes prevent under-ordering on delivery day.
Good dimensions improve ergonomics and plant health for years.
Common mistakes
Beds too wide
You end up walking on soil, compacting roots.
No drainage plan
Lined beds without outlets waterlog in wet seasons.
Filling with subsoil only
Poor structure and weeds — invest in a proper mix.
Skipping weed membrane under paths
Paths become the weediest part of the plot.
Ignoring irrigation
Raised beds dry faster — plan water access.
Tips from gardening experts
Orient for sun
North–south beds often give even light to rows.
Use corners wisely
Tall crops on the north edge reduce shade on neighbours.
Mulch the surface
Compost or straw mulch cuts watering frequency.
Crop rotate
Move plant families each year to reduce pests and disease.
Frequently asked questions
How much soil for a 2×1 m raised bed?
At 30 cm: 0.6 m³. At 45 cm: 0.9 m³. Multiply by the number of beds.
What is the best raised bed height?
30–45 cm suits most kitchen gardens. Go taller for accessibility or poor ground below.
How wide should a raised bed be?
About 1–1.2 m so both sides are reachable.
Do I need a bottom on the bed?
Usually no — open soil contact is healthier. Use mesh if voles are a problem.
What soil mix should I use?
Topsoil + compost is a reliable base; add grit on heavy sites.
Can I put raised beds on concrete?
Yes with enough depth and drainage holes; expect to water more.
How far apart should beds be?
40–60 cm paths are comfortable; wider if you use a wheelbarrow.
Will timber rot?
Untreated softwood eventually fails — choose durable timber or liners thoughtfully.
How often do I refill?
Top up each year as organic matter settles and composts down.
Can I mix vegetables and flowers?
Yes — companions can support pollinators. Use the Companion Planting Tool for pairings.
Sources and further reading
Want more detail? These pages from the Royal Horticultural Society (RHS), the UK’s gardening charity, explain the topic in depth.
Related guides
Related plants
Explore plants that pair well with this calculator’s job in the garden.
Related calculators
Calculator
Soil Calculator
Work out soil volume for beds and fills.
Calculator
Compost Calculator
Calculate compost for top-dressing and beds.
Calculator
Plant Spacing Calculator
How many plants fit in a bed.
Calculator
Watering Calculator
Seasonal watering advice by plant type.
Calculator
Mulch Calculator
Estimate mulch volume for beds and borders.
Downloads
Raised bed build checklist
Site, size, fill and first planting.
Bed layout PDF
Sample layouts (placeholder).
Get seasonal gardening advice
See what to sow, plant and prune each month in the Garden Plant Finder seasonal calendar.
Ready to choose plants?
Use Plant Finder filters for soil, sun, wildlife and flowering month — then plan quantities with these calculators.