Water Intake Calculator
Enter body weight in kg and exercise minutes to estimate daily water: 35 mL per kg plus 350 mL for each 30 minutes of exercise. 70 kg with 30 minutes of exercise gives about 2.8 L per day.
What this calculator does
The Water Intake Calculator estimates your result instantly from the values you enter, using standard health & fitness formulas. Enter body weight in kg and exercise minutes to estimate daily water: 35 mL per kg plus 350 mL for each 30 minutes of exercise. 70 kg with 30 minutes of exercise gives about 2.8 L per day. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Water Intake Calculator
The Water Intake Calculator combines a weight-based baseline of 35 mL per kg with an exercise top-up of 350 mL for every 30 minutes of activity. Enter your weight and exercise minutes to see a daily total in litres.
Formula & Mathematical Calculation
Daily Water (L) = f(Body Weight (kg), Exercise (minutes))
Calculated according to standard health formulas implemented in the calculator core.
Calculation Example
Enter Body Weight 70 kg and Exercise 30 minutes. The tool computes 35 x 70 + (30 / 30) x 350 = 2800 mL and shows Daily Water of 2.8 L.
Key Benefits
- Bases hydration on body weight at 35 mL per kg
- Adds an exercise allowance of 350 mL per 30 minutes
- Returns a daily total in litres to two decimals
- Only two inputs needed
How to Use this Calculator
-
Enter body weight
Type your Body Weight (kg). -
Enter exercise
Type your Exercise time in minutes. -
Calculate
Click Calculate and read the Daily Water (L) box.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Water Intake Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.