Water-Cement Ratio is defined as the ratio between the weight of the water to the weight of cement. In general terms, w/c ratio means how much water it requires for the particular mix. We all know that the water-cement ratio will directly affect the strength of concrete. The strength of concrete either increases or decreases will depend upon the w/c ratio. It can also affect the workability of concrete, which is most important to concreting process enjoy mixing, placing and compacting. Therefore, it’s most important to calculate the water-cement ratio while mixing design. As this is very important for both fresh and hardened concrete.

### Water-cement ratio table

Here we list the water-cement ratio table as per IS code 10262

### How to calculate the quantity of water for Concrete?

Normally, the water-cement ratio is between 0.4 to 0.6 as per IS standard.

We take 0.42 as a ratio of W/C.

Quantity of water = 0.42 x 50 = 21 Liters (1 bag cement = 50 Kg)

So the required quantity of water is 21 Liters per cement bag.

**We shall interpret the water-cement ratio by Thumb Rule Calculation for M15 grade concrete.**

#### M15 Ratio 1:2:4

cement = 317 Kg (unit weight = 1440 kg/cum)

Sand = 638 Kg (unit weight = 1450 Kg/cum)

Blue Metal = 1478 Kg (unit weight = 1680 Kg/Cum)

Total = 316.8+638+1478 = 2433 Kg

Unit Weight of Water = 1000 Kg

Water ratio = 1000/2433 = **0.41**