Enter the water uptake and body weight into the calculator to determine the Hydration Index. This calculator can also evaluate any of the variables given the others are known.

## Hydration Index Formula

The following formula is used to calculate the Hydration Index.

HI = (WU / BW)

Variables:

- HI is the Hydration Index (mL/g)
- WU is the water uptake (mL)
- BW is the body weight (g)

To calculate the Hydration Index, divide the water uptake by the body weight.

## What is a Hydration Index?

A Hydration Index is a measure used to determine how well a beverage hydrates the body compared to a standard reference, usually water. It takes into account factors such as the volume of fluid intake, the drink’s nutrient composition, and the body’s fluid balance over a certain period after consumption. This index is useful in understanding the hydration effectiveness of different beverages, which can aid in maintaining optimal hydration levels for health and performance.

## How to Calculate Hydration Index?

The following steps outline how to calculate the Hydration Index (HI).

- First, determine the water uptake (WU) in milliliters (mL).
- Next, determine the body weight (BW) in grams (g).
- Next, use the formula HI = (WU / BW) * 1000 to calculate the Hydration Index.
- Finally, calculate the Hydration Index.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem : **

Use the following variables as an example problem to test your knowledge.

Water uptake (WU) = 250 mL

Body weight (BW) = 500 g