Gardening Calculators
8 free calculators · Updated for 2026/27
Garden jobs are mostly a question of area and volume, and guessing either means a second trip to the garden centre or a stack of unused bags. Gardening calculators turn lawn areas, bed sizes, patio dimensions and pond shapes into quantities and costs, so a weekend of seeding, landscaping or building a raised bed can be priced and ordered in one go.
Seed for a new lawn, an overseeding job or a patch repair is measured by the Lawn Seed Calculator, which gives bag counts with costs. The Raised Bed Soil Calculator works out soil, bags and sleepers for a bed of a given size, the Patio Paving Calculator counts slabs along with the jointing sand, and the Pond Volume Calculator gives volume in litres plus pump size and liner dimensions. The Fence Paint Calculator sizes paint or stain from panels, height and coats.
Lawn Seed Calculator
Calculate grass seed needed for new lawns, overseeding or repair. Get bag counts and cost estimates.
Raised Bed Soil Calculator
Calculate soil, bags and sleepers needed for raised garden beds with common size presets.
Topsoil Calculator — Tonnes & Cost
Calculate topsoil needed in cubic metres, tonnes or bags for garden beds and landscaping.
Patio Paving Calculator
Calculate paving slabs needed for your patio or path. Includes jointing sand estimate.
Mulch Calculator — Bags & Coverage
Calculate mulch needed in litres and bags for garden beds and borders.
Greenhouse Size Calculator
Calculate greenhouse growing capacity. See how many plants fit by type with common size presets.
Pond Volume Calculator
Calculate pond volume in litres, pump size and liner dimensions for rectangle, circle or oval ponds.
Fence Paint Calculator
Calculate fence paint or stain needed based on panels, height and number of coats.