How much cement is required for 1m³ concrete?

Concrete is made up of different materials such as cement, sand, and aggregates. There are different grades of concrete-like normal grade, standard grade of concrete, and high strength grade of concrete.

M5 e.g. “M” represents for mix whereas “5” numerical value represents the overall characteristics compressive strength (N/mm2) of that particular mix at 28 days. The nominal mix ratio is prepared as per IS 456 code book.

Concrete grade	Type of concrete	Mix ratio
M5,M7.5,M10 , M15 ,M20	Nominal grade	Nominal mix ratio
M25,M30,M35 , M40 ,M45	Standard grade	Design mix ratio
M50,M55,M60 , M65 ,M70	High strength grade

Let’s calculate how much cement, sand, and aggregate are required for 1m3 of M20 concrete.

We know that wet volume of concrete = 1m3, but we need dry volume of concrete. To calculate  dry volume of concrete we have to multiply 1.54 to wet volume of concrete.

When we mix the dry materials together with water, the number of air voids present in the dry materials get evaporated and their volume is decreased by 54% after mixing. That’s a reason why dry volume of concrete is increased by 54% of wet concrete.

Step 1: Wet volume of concrete = 1m3

Dry volume of concrete = 1*1.54 (cubic meter)

Step 2: For Grade M20

Cement	Sand	Aggregate
1	1.5	3

Total mix proportion = 1+1.5+3=5.5

Part of Cement	Part of Sand	Part of Aggregate
1/5.5	1.5/5.5	3/5.5

Step 3: let’s calculate how much quantity of cement is required for M20 concrete in cubic meter.

(1/5.5)* 1.54 m3= 0.28m3.

So, 0.28 m3 cement is required for 1 cubic meter of M20 concrete.

Lets calculate this in the terms of bag.

1m3 of cement =1440kg

So, 0.28m3 of cement =1440*.28=403 kg

As we know, Each bag contain 50 kg

So the number of bags required =403/50=approx 8

So the number of Cement bags required is 8