Concrete Mix Ratios Explained: 1:2:4, 1:1.5:3, M25, and Water-Cement Ratio
Concrete mix ratio notation (1:2:4, 1:1.5:3, M20, M25) tells you the proportion of cement, sand, and aggregate by volume or weight. This guide decodes nominal mixes, design mixes, and IS/BS designation systems — with worked examples, w/c ratio guidance, and a direct comparison of every standard grade from M5 to M40.