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Water Intake Calculator: a practical daily starting point
Use your body weight and today's training time to set a transparent starting point for fluids, then adjust for thirst, heat and your own response.
Already know your numbers? Start tracking free in Prime Adapt →Already on Android? Get the Prime Adapt app on Google Play →Questions people ask
How is the estimate worked out?
It starts at 35 mL per kg of body weight and adds a modest training-time allowance. It is a planning number, not a prescription.
Does coffee count?
Fluids in drinks and food contribute to hydration. Caffeine does not automatically cancel the fluid in a drink, but this calculator is intentionally simple.
Should I drink more when it is hot?
Usually, heat and sweating change needs. Use thirst, urine colour, sweat loss and local advice rather than treating this estimate as a ceiling.
When should I ask for medical advice?
Ask a clinician if you have kidney, heart or liver disease, a fluid restriction, or symptoms such as confusion, fainting or persistent vomiting.