Health calculator
Water Intake Calculator
Estimate daily water intake from body weight and activity adjustment.
FormulaDaily water = body weight x 35 ml, adjusted for activity
Formula
Water intake estimate
Hydration needs vary with climate, health, medications, diet, pregnancy, and activity.
Daily water = body weight x 35 ml, adjusted for activity
70 kg x 35 ml = 2,450 ml before activity adjustment.
FAQ6 common questions for this calculator.
FAQs
Is the water intake estimate medical advice?+
No. It is a general hydration estimate.
Should athletes drink more?+
Often yes, especially during heat, long workouts, or heavy sweating.
How does the Water Intake Calculator calculate the result?+
For the Water Intake Calculator, it uses the Water intake estimate: Daily water = body weight x 35 ml, adjusted for activity. 70 kg x 35 ml = 2,450 ml before activity adjustment.
What information do I need to use the Water Intake Calculator?+
For the Water Intake Calculator, enter body weight and activity adjustment. Keep the units consistent with the calculator fields and compare your setup with the worked example on the page.
How accurate is the Water Intake Calculator?+
Water Intake Calculator is only as accurate as the body weight and activity adjustment entered. It applies the Water intake estimate shown on this page, then rounds for readability. Treat the output as screening guidance rather than a diagnosis.
What should I check before using the Water Intake Calculator result?+
For the Water Intake Calculator, check body weight and activity adjustment, unit choices, and whether the calculator's assumptions fit the person being assessed. Use the result as screening or planning context, not as a diagnosis.
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Health guide
How to use the Water Intake Calculator
Estimate daily water intake from body weight and activity adjustment. The page also explains the water intake estimate and shows a practical example: 70 kg x 35 ml = 2,450 ml before activity adjustment.
- 1
Enter your details
Enter body weight and activity adjustment, then complete any other fields shown in the calculator.
- 2
Check the calculation
Review the result alongside the water intake estimate: Daily water = body weight x 35 ml, adjusted for activity.
- 3
Compare scenarios
Change one or more inputs to see how they affect the water Intake Calculator result before you use the estimate.