Theme console livePreset skins and colour tokens update the interface immediately in this browser session.
Water Intake Calculator
Estimate a daily water target from body weight, exercise minutes, climate adjustment and pregnancy/breastfeeding context.
Live math canvas
Your numbers, formula and explanation together
Water Intake Calculator: 3.16 L/day. 2.8 L base + 0.36 L exercise + 0 L climate/context + 0 L pregnancy/lactation context.
Formula applied
The exact method behind this answer
CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.
Base water = 35 mL × body weight kg. Exercise allowance = 12 mL × exercise minutes. Climate allowance = 0, 500 or 1,000 mL. Pregnancy/lactation allowance = 0, 300 or 700 mL.
Apply the formulaBase water = 35 mL × body weight kg. Exercise allowance = 12 mL × exercise minutes. Climate allowance = 0, 500 or 1,000 mL. Pregnancy/lactation allowance = 0, 300 or 700 mL.3.16 L/day2.8 L base + 0.36 L exercise + 0 L climate/context + 0 L pregnancy/lactation context.
Your live breakdown
Current inputs in the calculation
These values come from the controls above and update when the calculator changes.
Body weight
80 kg
Exercise time
30 min/day
Climate/activity heat
Normal
Pregnancy/lactation
No extra
Resulting answer
3.16 L/day
2.8 L base + 0.36 L exercise + 0 L climate/context + 0 L pregnancy/lactation context.
Answer
3.16 L/day
Live support
2.8 L base + 0.36 L exercise + 0 L climate/context + 0 L pregnancy/lactation context.
Assumptions used
What this answer assumes
The visible assumptions define the boundary of this calculation.
This is a rough hydration planning estimate, not medical advice.
Food, other drinks, climate, medication and health conditions affect fluid needs.
Very high or very low fluid intake should be discussed with a qualified professional.
Master’s Tip
How to use the result well
Master’s Tip: use thirst, urine colour, heat, sweat, salt intake and clinical conditions as context, not just a formula.
Printable record
What belongs in the saved calculation
Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.
Body weight
80 kg
Exercise time
30 min/day
Climate/activity heat
Normal
Pregnancy/lactation
No extra
Embeddable calculator
Embed this calculator
Copy a clean iframe version with the required CalculationTime attribution link built in.
Explain it like I'm 12
The water intake calculator starts with body-weight-based fluid needs and adds practical allowances for exercise, hot conditions and pregnancy or breastfeeding context.
Base water = 35 mL × body weight kg. Exercise allowance = 12 mL × exercise minutes. Climate allowance = 0, 500 or 1,000 mL. Pregnancy/lactation allowance = 0, 300 or 700 mL.
Worked example
For 80 kg and 30 exercise minutes in normal climate, base water is 2.8 L and exercise allowance is 0.36 L, giving about 3.16 L/day.
Professional note
Master’s Tip: use thirst, urine colour, heat, sweat, salt intake and clinical conditions as context, not just a formula.
Regional and unit assumptions
Metric hydration planning estimate.
Assumptions and limitations
This is a rough hydration planning estimate, not medical advice.
Food, other drinks, climate, medication and health conditions affect fluid needs.
Very high or very low fluid intake should be discussed with a qualified professional.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
Base water = 35 mL × body weight kg. Exercise allowance = 12 mL × exercise minutes. Climate allowance = 0, 500 or 1,000 mL. Pregnancy/lactation allowance = 0, 300 or 700 mL.
Standard or basis
Metric hydration planning estimate.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.
Master's Tip
Master’s Tip: use thirst, urine colour, heat, sweat, salt intake and clinical conditions as context, not just a formula.
Related calculators
Next calculations from the same record
These cards are resolved from calculator data, category context and live-route status so the page links to useful next steps without hand-built link clutter.