Water Intake Calculator

Drinking enough water is essential for health and performance.

What this calculator does

Guideline: 35 ml per kg of body weight. More for exercise and heat.

When to use this calculator

Reach for this calculator when you need a standardised health metric to discuss with a healthcare provider or to use as a baseline for a fitness programme. The result gives you a number that carries more meaning than subjective assessments.

Common mistakes

Many users apply adult health classifications to children and teenagers, which is incorrect. Paediatric norms for height, weight, BMI, and body composition are age-and-sex-specific. Use age-appropriate reference tools for anyone under 18.

Real-world scenarios

A personal trainer uses the calculator with a new client to set a measurable starting point. Re-running the calculation at 4-week intervals provides an objective progress metric that supports motivation and programme adjustments.

Frequently asked questions

How much water should I drink per day?

About 2-3 liters on average, depending on weight, activity, and climate.

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