Calculate paving slabs, sand, cement, and sub-base materials for patios and landscaping.
A well-built patio needs a properly prepared sub-base, the right bedding mix, and enough slabs to cover the area with a reasonable waste margin for cuts. Skimping on sub-base depth is the main reason patios sink and crack within a few years. This calculator assumes a minimum 100mm compacted MOT Type 1 sub-base for pedestrian use. Adjust the depth upward for areas taking vehicle traffic. Bedding mortar is calculated at a standard 4:1 sand-to-cement ratio for a full mortar bed, which gives the strongest result for natural stone and concrete slabs.
Part of Builder Tools Calculators — free construction tools for UK tradespeople.