Daily Water Intake Calculator
Use this daily water intake calculator for an approximate adult fitness calculation. Choose US units for pounds, inches or yards, or switch to metric. Results are estimates, not medical or training prescriptions.
Your Numbers
Results
Results update live as you type. Estimates only — not financial, tax, or investment advice.
The Formula
Daily Water (ml) = (Body Weight kg × 35 ml) + (Exercise minutes ÷ 30 × 350 ml)
Understanding the Daily Water Intake Calculator
Worked example: At 80 kg (176.4 lb), a chosen baseline of 35 mL/kg and 45 exercise minutes produce 2,800 + 525 = 3,325 mL, approximately 112.4 US fluid ounces.
This is a configurable arithmetic heuristic, not a validated hydration prescription. Fluid needs depend on food, heat, sweat losses and medical conditions; do not force fluid intake to match the result.
Frequently Asked Questions
How is the result calculated?
Daily Water (ml) = (Body Weight kg × 35 ml) + (Exercise minutes ÷ 30 × 350 ml)
What should I know about this estimate?
This is a configurable arithmetic heuristic, not a validated hydration prescription. Fluid needs depend on food, heat, sweat losses and medical conditions; do not force fluid intake to match the result.