Health / ACTUALLY USEFUL
Daily water intake estimate
Explore a fluid-planning estimate for your size, weather and activity.
YOUR NUMBERSResults update as you type
Illustrative daily fluid total2.3litres
Equivalent 250 ml cups9.2cups
Baseline portion2.1litres
This weight-based model is an adjustable heuristic, not an NHS recommendation. NHS guidance is generally 6–8 cups/glasses daily, with more sometimes needed in heat or prolonged activity. Other drinks and food contribute fluids.
Method & assumptions
For adults only; a planning estimate, not a diagnosis or personalised treatment. Not suitable for pregnancy, breastfeeding or conditions requiring clinical nutrition or exercise advice. Do not force fluid intake or use this if you have a prescribed fluid restriction. Sweat losses vary; excessive water intake can be harmful. Follow thirst and clinical advice rather than a rigid calculated target.
SOURCES · CHECKED 12 SEPTEMBER 2026