As we know that  during concreting when we place wet concrete , it gets harden after certain standard time( 30 mins IST & 10hrs FST), considering same it had be decided upon by Civil design Engineers to take a factor of safety ranging from 1.54 to 1.57 to counter that shrinkage.

 Assumptions

Volume of concrete = 1 m³

Grade of concrete M20 (1:1.5:3)

Find-out the Quantity of concrete (Wet volume and Dry volume)

Wet volume of concrete = 1 m³

Dry volume = Wet volume x 1.54 (You can also take it as 1.50 to 1.55, But it became standard practice to considering 1.54 as multiplication factor).

Dry volume of concrete = 1 x 1.54 =1.54 m³

1- Find-out quantity of Cement

Quantity of cement = (Dry volume of concrete x cement ratio)/(sum of the ratio)

Cement = (1.54 x 1)/(1+1.5+3)=0.28 m³

Density of Cement = 1440 kg/m³

Weight of Cement = 1440 x 0.28 = 403.2 Kg

1 bag of cement contains 50 kg of cement

Number of bags = 403.2 Kg/50 kg = 8.064 ≅8 No’s

2- Find-out quantity of Sand

Cement : Sand :: 1:1.5

Quantity of sand =Quantity of cement x 1.5

Quantity of Sand = 0.28 x 1.5 =0.42 m³

or Quantity of sand =( 1.5/5.5) * 1.54= 0.42 m³

1 m³=35.3147 Cubic Feet (CFT)

Quantity of sand = 0.42 x 35.3147 = 14.832 CFT

Weight of sand = volume x density, Density of Sand = 1650 kg/m^3

 Weight of sand= 0.42 x 1650= 693 kg (0.693 tonnes)

3- Find-out quantity of Coarse Aggregates

Cement : Coarse Aggregates :: 1:3

Quantity of Coarse Aggregates =Quantity of cement x 1.5

Quantity of Coarse Aggregates = 0.28 x 3 =0.84 m³

or Quantity of coarse aggregates = (3/5.5)*1.54 = 0.84 m³

 1 m³=35.3147 Cubic Feet (CFT)

Quantity of Coarse Aggregates = 0.84 x 35.3147 = 29.664 CFT

Weight of Coarse Aggregates = volume x density, Density of Coarse Aggregates = 1520 kg/m^3

Weight of Coarse Aggregates = 0.84 x 1520 = 1276.8 kg (1.28 tonnes)

The above calculation you can use for all Grade of Concrete but just you have to put the different Grade of concrete like M10, M 15, M20, M25 etc. just here with grade of concrete you can change the proportion and the method is just above which I have discuss .

Different grades of concrete 

Different grades of concrete has different Concrete Mix proportions which means different concrete mix ratios. As Per IS456:2000, the Concrete mix design has the following concrete mix proportions :-