GRADES OF CONCRETE

 Nominal Mix Concrete:

Grades of Concrete	Mix Ratio Cement:Sand:Aggregate	Compressive strength of 150 mm cube at 28 days cured MPa (N/mm2)     Psi
M5	1:5:10	5 Mpa	725 Psi
M7.5	1:4:8	7.5 Mpa	1087 Psi
M10	1:3:6	10 Mpa	1450 Psi
M15	1:2:4	15 Mpa	2175 Psi
M20	1:1.5:3	20 Mpa	2900 Psi
M25	1:1:2	25 Mpa	3625 Psi
M30 and above	Design Mix	30 Mpa	4350 Psi

Grades of Concrete as per IS 456:

Group	Grade Designation	Specified Characteristic Compressive strength of 150 mm cube at 28 days in N / mm2
Ordinary concrete	M10	10
	M15	15
	M20	20
Standard Concrete	M25	25
	M30	30
	M35	35
	M40	40
	M45	45
	M50	50
	M55	55
High Strength	M60	60
	M65	65
	M70	70
	M75	75
	M80	80

Note:  

(1) M5 and M7.5 Grades may be used for lean concrete bases and simple foundations for masonry walls. These mixes need not be designed.

(2) Grades lower than M15 shall not be used in reinforcement concrete.

Different Grades of Concrete -- Concrete Mix Design