What does the Raised Bed Soil Calculator do?

Calculate soil, bags and sleepers needed for raised garden beds with common size presets. All calculations are performed in your browser using official UK rates and thresholds.

Does this include delivery costs?

This calculator estimates material quantities and approximate costs. Delivery charges vary by supplier, quantity and location. Bulk orders often qualify for free or reduced delivery.

When is the best time for this project?

Timing depends on the specific project. Generally, spring and autumn are ideal for lawn and planting work, while hard landscaping can be done year-round in dry conditions.

Raised Bed Soil Calculator

Calculate soil, bags and sleepers needed for raised garden beds with common size presets.

Last updated: April 2026 · Source: RHS — Raised beds

Length (m)

Width (m)

Depth (mm)

Bag Price (£)

Bag Size (litres)

Soil Needed

864 litres

50L Bags

Soil Cost

£108.00

Sleepers (2.4m)

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

Raised bed soil volume is calculated as length × width × depth. A depth of 200–300 mm suits most vegetables and flowers; deeper beds (400–600 mm) are needed for root crops and fruit. The RHS recommends filling raised beds with a mix of topsoil (60–70%), compost (20–30%) and sharp sand or perlite (5–10%) for good drainage.

This calculator also estimates the timber or sleeper quantity needed to build the bed frame. Standard options include treated softwood boards (150 × 22 mm, stacked 2–3 high), railway sleepers (200 × 100 mm) and composite boards. Corner posts, screws and weed membrane are included in the materials list.

Enter the bed dimensions. The calculator shows soil volume in litres and bulk bags, plus a bill of materials for the frame. A 1.2 m × 2.4 m bed at 300 mm deep is a popular size — wide enough for a double row of plants but narrow enough to reach the centre from either side without stepping on the soil.

Example: Raised bed 2.4 m × 1.2 m × 0.3 m deep

Volume: 2.4 × 1.2 × 0.3 = 0.864 m³ (864 litres)
Soil mix: ~600 L topsoil + ~220 L compost + ~44 L sharp sand
Timber: 6 boards at 2.4 m + 6 boards at 1.2 m (150 × 22 mm, 3 courses)
Corner posts: 4 × 350 mm (50 × 50 mm)
Estimated fill cost: £60–£100 (bulk bags)

Source: RHS — Raised beds

Frequently Asked Questions

What does the Raised Bed Soil Calculator do?: Calculate soil, bags and sleepers needed for raised garden beds with common size presets. All calculations are performed in your browser using official UK rates and thresholds.
Does this include delivery costs?: This calculator estimates material quantities and approximate costs. Delivery charges vary by supplier, quantity and location. Bulk orders often qualify for free or reduced delivery.
When is the best time for this project?: Timing depends on the specific project. Generally, spring and autumn are ideal for lawn and planting work, while hard landscaping can be done year-round in dry conditions.