Water Intake Calculator
Calculate how much water you should drink per day.
Hydration needs are estimates and do not replace medical advice.
Water intake calculator
Enter your weight, activity level, and environment for a planning estimate.
Switching units converts your current weight instead of changing its meaning.
Estimated daily water target
2.5 L
Approximately 2,450 mL per day.
Ounces per day
83 oz
Cups per day
10 cups
500 mL bottles
4.9
Baseline estimate
2.5 L
Uses standard hydration estimation math. Reviewed for arithmetic accuracy. Estimate only. Does not replace medical advice or prescribed fluid restrictions.
Personalized hydration interpretation
Based on your inputs, your estimated daily water target is about 2.5 litres, or 83 ounces.
The baseline estimate is 2.5 litres. Activity, climate, pregnancy, and breastfeeding adjustments are added on top when selected.
Activity and hot weather can increase fluid needs.
Food, tea, coffee, milk, and other drinks can contribute to total fluid intake.
If you have a medical condition or fluid restriction, follow your healthcare professional’s guidance.
Very high water intake can be unsafe, especially if electrolytes become diluted.
What counts toward daily fluid intake
Hydration needs by activity and climate
Fluid needs may increase with exercise, heat, sweating, altitude, illness, and some dietary patterns. Individual needs differ.
Water intake vs total fluid intake
Water intake
Usually means plain water consumed during the day.
Total fluid intake
Includes water, other beverages, and some water from foods.
Signs you may need more or less fluid
Possible low-fluid signs
Thirst, dark urine, dry mouth, headache, fatigue, or dizziness may provide context.
Possible excess-fluid signs
Nausea, confusion, swelling, severe headache, or symptoms after excessive water intake should be taken seriously.
Urine colour can be affected by vitamins, medications, foods, and health conditions.
Accuracy limits and healthy context
Calculators are planning tools. Medical fluid needs can be different, and trends, symptoms, medications, and professional guidance matter.
Formula explanation
Baseline Water Estimate = Body Weight × Water FactorBody Weight in kg = kg input OR lbs × 0.45359237Daily Water in mL = Body Weight in kg × 35 mLTotal Estimate = Baseline + Activity + Climate + Pregnancy/BreastfeedingExample 1
70 kg × 35 mL/kg = 2,450 mL, or about 2.45 L/day.
Example 2
160 lb converts to about 72.6 kg. 72.6 × 35 ≈ 2,541 mL/day.
Example 3
A 2,450 mL baseline plus a 590 mL activity adjustment gives about 3,040 mL.
Frequently Asked Questions
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