Hangover Hydration Calculator

About this calculator

Alcohol suppresses the antidiuretic hormone (vasopressin) that normally helps your kidneys conserve water, so you lose more fluid than you actually drank — a major contributor to hangover symptoms the next morning. Rehydration needs can be estimated from how much and what you drank relative to your body weight.

It’s used casually the morning after drinking to figure out roughly how much water to catch up on, often alongside advice to replace electrolytes lost the same way.

This calculator takes the drinks you consumed and your body weight, and returns an estimated rehydration fluid volume.