Garden calculators
Garden and landscaping tools for planting, lawns and material quantities.
Topsoil calculator
How much topsoil you need for a bed, border or levelling job.
Compost calculator
How much compost you need to mulch or improve a bed.
Mulch calculator
How much bark or wood-chip mulch you need, with a reverse mode.
Gravel calculator
How much gravel you need for a path or driveway.
Grass seed calculator
How much grass seed you need to sow or overseed a lawn.
Turf calculator
How many turf rolls you need to lay a new lawn.
Raised-bed soil calculator
How much soil mix you need to fill a raised bed.
Plant-spacing calculator
How many plants fit into a bed on a regular grid.
Pond volume calculator
Estimates a pond's water volume from its dimensions.
Hedge plant calculator
How many hedging plants you need for a single-row hedge.
Fence panel calculator
How many fence panels and posts you need for a fence run.
Decking calculator
How many deck boards you need for a deck area.
Working out garden material quantities
Loose materials — topsoil, compost, mulch and gravel — use geometric volume: area multiplied by entered depth. Doubling the depth doubles the calculated volume. That arithmetic does not determine an appropriate application depth or predict settling, compaction, moisture or product-specific yield; choose depth for the material and purpose.
Bags or bulk
Suppliers sell by the litre, by the bag or by the cubic metre (often as a bulk bag). Check the volume of the bag you're buying and compare against the calculated volume rather than assuming bag sizes.
Settling and compaction
Actual settlement and compaction depend on material, ground and use. Waste/extra allowances are estimates rather than fixed rates; consider the project and supplier's information, and distinguish delivered volume from any later compacted or settled depth.
Counting items
Plant counts depend on the entered spacing and layout model, not just bed area. The plant-spacing calculator counts positions on a square grid; use species-specific guidance for spacing and account separately for edge setbacks, mature spread and access.