## How to calculate compressive strength of concrete?

approximately about 70% of the grade strength of the concrete and For 28 days test result the strength to be ga by approximately 100 % of the grade strength of the concrete. Normally the unit of compressive strength as KG/SQMM , N/SQMM. As per thumb rule , at the time of weighg the cubes the mimum weight of cubes are 8.6 kg .