On average, the total fluids of a human body make up 60% of body weight. It is important to replenish losses daily, as water is one of the cornerstones of human health.
The intake recommendation is individualized but generally recommended for young adults is 35-40mg/kg body weight, while at least 25-30mg/kg body weight is recommended for older adults.
How much water did you drink yesterday and how much did you need?