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ToolWrenEstimate how much water you should drink each day based on your body weight and exercise.
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Water Intake is a free, private online tool that lets you estimate your recommended daily water intake from body weight and activity. It runs entirely in your browser, so nothing you enter is uploaded to a server.
Privacy: this tool runs entirely in your browser. Your input is never sent to, received by, or stored on any server — there are no uploads and no tracking of what you enter.
Water supports nearly every function in your body. A common guideline is around 33 ml per kilogram of body weight, with extra to replace fluid lost during exercise.
Choose metric or imperial, enter your weight and your daily exercise minutes, and the tool estimates your intake in liters, cups and fluid ounces.
Needs vary with climate, altitude, health conditions, pregnancy and diet (food provides water too). Use this as a starting point and listen to your body.
Water is involved in almost every bodily process - regulating temperature, transporting nutrients, cushioning joints and removing waste. Even mild dehydration affects concentration, energy and physical performance. This calculator estimates a sensible daily water target based on your body weight and activity level.
A widely used guideline is roughly 33 ml of water per kilogram of body weight per day, with extra to replace fluid lost through exercise. The tool applies this to your weight (metric or imperial) and adds an allowance for the minutes you exercise, then shows the result in litres, US cups and fluid ounces so you can track it however you prefer.
The famous eight 8-ounce glasses rule is a rough rule of thumb, not science - actual needs vary widely with body size, activity, climate and diet. A weight-based estimate like this one is more personalised. Remember too that food contributes water (fruit, vegetables and soups especially), and other drinks count toward intake.
Several things raise your requirement: hot or humid weather, high altitude, intense or prolonged exercise, fever or illness, pregnancy and breastfeeding. A practical real-world check is urine colour - pale straw suggests good hydration, dark yellow suggests you need more. Use the calculated figure as a baseline and adjust to conditions.
This is a general wellness estimate, not medical advice. Certain conditions (kidney or heart problems) require specific fluid management, and drinking excessively can occasionally be harmful. If you have health concerns, follow your doctor's guidance. Everything is calculated in your browser.