The old "8 glasses a day" rule ignores the biggest factor: you. Your ideal water intake depends on your body weight, how much you sweat, and your environment. This calculator estimates a sensible daily target using weight-based hydration guidance used in sports and clinical nutrition.
About this tool
Remember: About 20% of daily fluid comes from food — fruit, vegetables, soups and even coffee count toward hydration. Thirst and pale-yellow urine are reliable signs you are on track. People with kidney or heart conditions may need individualized fluid targets — ask your doctor.
This tool is for general information and screening purposes only. It is not medical advice and cannot diagnose any condition. Always consult a qualified healthcare professional about your health.