Calculator
Water intake calculator
Hydration is easy to lose track of when you are eating less, and it is one of the few things a daily record makes obvious. This gives a figure to log against.
How it is worked out
The derivation
water (ml) = body weight in kg × 33, rounded to the nearest 50 ml. An 82 kg body weight gives about 2,700 ml, or 2.7 litres.
Why round
A figure to the millilitre implies a precision nobody logs to. Rounding to 50 ml keeps it honest and easier to hit.
What shifts it
Heat, exercise, illness and some medications all change fluid needs, and certain heart and kidney conditions require fluid limits set by a clinician. A weight-based figure cannot know any of that.
Common questions
Do tea and coffee count?
Is more always better?
This is general wellness information
Cafeity does not diagnose, treat or prevent any condition, and never recommends, calculates or adjusts a medication dose. Anything on this page is arithmetic you can check, not advice. Questions about your treatment belong with a licensed healthcare professional.
Other calculators
- Protein calculator — A daily protein figure from body weight, using the same 1.4 g/kg derivation as the app.
- Fibre intake reference — The 25 g daily reference the app logs against, and how it is counted.
- BMI calculator — Body mass index from height and weight, plus what it does and does not measure.
- TDEE calculator — BMR and total daily energy expenditure via Mifflin–St Jeor, shown as an estimate.