Patio & Landscaping Calculator

How to use the Patio & Landscaping Calculator

1. Enter the measured patio length and width.
2. Choose an individual slab size or enter the coverage printed on your mixed-pack label.
3. Set the cutting allowance, compacted sub-base, bedding and excavation depths for the project.
4. Choose site-mixed or bagged bedding, then choose brush-in compound or sand-and-cement pointing and review the calculated quantities.

Why use this tool

• Checks both orientations for rectangular slabs and applies an editable cutting allowance.
• Shows recognisable order quantities for bedding and jointing, including sand, cement bags, mortar bags or named tubs.
• Shows compacted and ordering quantities separately, then allows for excavation bulking before suggesting waste removal.

This is an ordering estimate, not a paving-system design. The calculator starts with editable example depths, bag yields and product coverage, adds a visible 10% ordering allowance, and uses approximate bulk densities for sand, sub-base and excavation weights. Brush-in coverage is scaled from a published reference using the selected slab and joint dimensions; real joint profiles and laying patterns vary. Confirm that the paving manufacturer's bedding, primer and jointing instructions form a compatible system, together with the required compacted sub-base, finished levels, falls and drainage. Skip names are volume guides only because soil and rubble weight limits can control the load. Locate buried services before excavation and get competent advice where drainage, retaining work or changes of level could affect a building or neighbouring land.

Part of Builder Tools Calculators — construction tools for UK tradespeople.