Water Intake Calculator

Daily hydration target from weight, activity and climate

Updated for 2026
Formulas verified
No registration
100% free
Water
Hydration
ml
Profile

Water intake calculator

Estimate your daily hydration target — guidelines only, not medical advice

Why trust us?

  • Estimated calculations
  • Formulas are publicly known
  • Not medical advice
  • See "How do we calculate?" section

How it works

Starts from about 35 ml per kg body weight, then adds adjustments for activity, climate and optionally pregnancy or breastfeeding. Advanced mode includes workout duration and extra heat.

The result is an approximate guide, not medical advice. Some fluids come from food too. Save the target to your profile and track daily intake in the Water tab.

Frequently Asked Questions

How much water do I need per day?

It depends on weight, activity, climate and more. This calculator gives a practical estimate — use it as a starting point.

How do I save to my profile?

After calculating, tap “Save target to profile”. The daily goal appears in the Water tab where you can log intake.

Water Intake Calculator 2026 | Calculators BG