Metric calculator for concrete
Paving mix 1:3½ cement:allin ballast or 1:1½:2½ cement:sharp sand:gravel. General metric mix 1:5 or 1:2½:3½ . Enter the finished volume of the work then select 'Calculate now !': cubic metres . Note: this calculator allows for the concrete 'shrinkage' The materials needed are approximately: Portland cement : tonne : 50kg bags : Sharp sand : tonne : cubic metres : .