Water Intake Calculator
Free online water intake calculator. Find how much water to drink per day based on your body weight and exercise — in liters, ml, cups, and ounces.
About This Free Online Water Intake Calculator
Our free online water intake calculator estimates how much water you should drink each day based on your body weight and how much you exercise. Enter your weight and your daily exercise minutes, choose metric or imperial, and it shows a recommended daily target in liters, milliliters, cups, and fluid ounces. The estimate uses a common guideline of around 33 ml of water per kilogram of body weight, plus extra for exercise to replace what you lose through sweat. It runs entirely in your browser with no signup. Your needs also depend on climate and health, so treat the result as a helpful starting point.
Features of Our Water Intake Calculator
- Daily water target from body weight and exercise
- Results in liters, ml, cups, and fluid ounces
- Adds extra water for exercise time
- Metric (kg) and imperial (lb) units
- Simple, evidence-based guideline
- 100% free, no signup — runs in your browser
How to Use the Water Intake Calculator
Using this tool is simple and requires no signup or registration. Follow these steps:
- Choose your units and enter your body weight.
- Enter how many minutes you exercise per day.
- Read your recommended daily water in liters, ml, cups, and ounces.
- Copy or download your hydration target.
Frequently Asked Questions About Water Intake Calculator
How much water should I drink a day?
A common guideline is about 30–35 ml per kilogram of body weight, plus extra for exercise. For many adults that is roughly 2–3 liters a day. This calculator personalizes it to your weight and activity.
Does exercise change how much water I need?
Yes. You lose water through sweat, so active days need more. This tool adds roughly an extra cup of water for every 30 minutes of exercise on top of your baseline.
Do other drinks and food count?
Yes — tea, coffee, milk, and water-rich foods all contribute to hydration. The number here is a total daily water target; you do not have to get every drop from plain water.
Why Choose Text Toolbox?
Text Toolbox provides free, private, and instant online text tools. Unlike other text utility websites that require signup accounts or send your data to servers, all our tools process your text entirely in your browser. This means your content never leaves your device — we cannot see it, store it, or share it. Our tools are fast, lightweight, and work on any device with a modern web browser.