Work out what you need
Garden
Calculate quantities, understand the method and turn the result into a practical buying plan.
Calculators
Soil & Compost Calculator
Plan soil, compost, topsoil and raised-bed layers with bag or bulk quantities.
Use calculator →02Mulch Calculator
Calculate mulch or bark from area and depth, or use a supplier’s stated litres-per-area rate.
Use calculator →03Plant Spacing Calculator
Plan rectangular grids, staggered rows, hedges or bulbs and round to purchase packs.
Use calculator →04Container Soil Calculator
Calculate potting mix for round, tapered and rectangular containers.
Use calculator →05Lawn Seed Calculator
Estimate grass seed from lawn area and the packet sowing rate.
Use calculator →06Fertilizer Quantity Calculator
Calculate fertilizer from treatment area and label application rate.
Use calculator →07Gravel Path Calculator
Calculate path volume, supplier-density weight and bag quantities.
Use calculator →08Watering Volume Calculator
Translate an entered water-depth target into volume after rainfall and application losses.
Use calculator →09Turf Roll Calculator
Work out the lawn area, the turf coverage needed and the whole rolls to order after allowing for cuts.
Use calculator →Practical guides
Guide
How Much Soil Do I Need?
Calculate bed volume from area and depth, allow for settlement, convert to bags or bulk tonnes, and choose the right soil product for the job.
Read guide →Guide
Raised Bed Soil Depth Guide
Choose fill depth according to bed construction, crop roots and existing ground.
Read guide →Guide
How to Fill a Raised Bed
How deep to fill a raised bed, what mix to use, how much soil and compost to buy, and how to allow for settlement, with RHS guidance and a worked example.
Read guide →Guide
Mulch Depth Guide
How deep to spread mulch (the RHS suggests 5–7.5 cm), how to keep stems clear, and how to turn a depth into litres and bags.
Read guide →Guide
Mulch Types Explained
Compare organic and mineral mulches by purpose, depth and replenishment.
Read guide →Guide
Garden Soil Buying Guide
Choose soil by intended use, usable volume and delivery format after calculating the quantity.
Read guide →Guide
Topsoil vs Compost vs Raised-Bed Mix
What topsoil, compost and raised-bed mixes each do, the RHS proportions for a standard raised-bed mix, and how to compare products.
Read guide →Guide
Raised-Bed Drainage and Liner Guide
Plan the base, drainage and internal protection without blocking healthy root growth.
Read guide →