Water Intake Calculator
Calculate how much water you should drink daily based on weight, activity level, and climate. Stay hydrated with our guide.
Today's Log
Method and limits
This illustrative equation is max(1.5, kg × 0.033 + activity + climate) L/day; it is not a validated individual water prescription.
Activity adds 0 / 0.35 / 0.7 / 1.0 / 1.4 L; climate adds −0.2 / 0 / 0.5 / 0.8 L. 1 lb = 0.45359237 kg.
EFSA references include drinks AND food moisture: 2.0 L/day for adult females and 2.5 L/day for adult males at moderate activity and temperature. They do not validate this weight-based equation or this drinking log target.
Litres use one decimal; 250 mL glasses use the nearest whole number. Progress and remaining use the visible rounded target.
- Choose weight, unit, activity and climate to explore the illustrative scenario.
- Add a portion; undo the latest entry or reset the displayed day. The dated log rotates when the page checks the local date.
70 kg, light activity, temperate: 2.66 L before display rounding → 2.7 L and 11 glasses. Two 250 mL portions = 500 mL; undo = 250 mL.
This page calculates locally. Only this tracker log and its dated archives are saved in this browser; they are not synced. Copying runs on request. Other site services have their own behavior.
Sources: EFSA (2010)
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About Water Intake Calculator
Calculate recommended daily water intake. Track glasses and stay hydrated. Personalized based on weight, activity, and climate factors.
This illustrative equation is max(1.5, kg × 0.033 + activity + climate) L/day; it is not a validated individual water prescription. EFSA references include drinks AND food moisture: 2.0 L/day for adult females and 2.5 L/day for adult males at moderate activity and temperature. They do not validate this weight-based equation or this drinking log target. This page calculates locally. Only this tracker log and its dated archives are saved in this browser; they are not synced. Copying runs on request. Other site services have their own behavior.
70 kg, light activity, temperate: 2.66 L before display rounding → 2.7 L and 11 glasses. Two 250 mL portions = 500 mL; undo = 250 mL.
Activity adds 0 / 0.35 / 0.7 / 1.0 / 1.4 L; climate adds −0.2 / 0 / 0.5 / 0.8 L. 1 lb = 0.45359237 kg.
Use Cases
How to use
Enter your weight
Select activity level
Consider climate factors
View daily water recommendation
Choose weight, unit, activity and climate to explore the illustrative scenario.
Add a portion; undo the latest entry or reset the displayed day. The dated log rotates when the page checks the local date.
Pro Tips
- General rule: half your weight in pounds = oz of water
- Increase intake during exercise or hot weather
- Food provides about 20% of water intake
- Activity adds 0 / 0.35 / 0.7 / 1.0 / 1.4 L; climate adds −0.2 / 0 / 0.5 / 0.8 L. 1 lb = 0.45359237 kg.
- Litres use one decimal; 250 mL glasses use the nearest whole number. Progress and remaining use the visible rounded target.
Frequently Asked Questions
Typically 8 glasses (64oz) is recommended, but needs vary by person. This illustrative equation is max(1.5, kg × 0.033 + activity + climate) L/day; it is not a validated individual water prescription. EFSA references include drinks AND food moisture: 2.0 L/day for adult females and 2.5 L/day for adult males at moderate activity and temperature. They do not validate this weight-based equation or this drinking log target.
Yes, overhydration is possible but rare. Listen to your thirst. This illustrative equation is max(1.5, kg × 0.033 + activity + climate) L/day; it is not a validated individual water prescription. EFSA references include drinks AND food moisture: 2.0 L/day for adult females and 2.5 L/day for adult males at moderate activity and temperature. They do not validate this weight-based equation or this drinking log target.
Water is best, but other beverages contribute. Coffee/tea count despite mild diuretic effect. This illustrative equation is max(1.5, kg × 0.033 + activity + climate) L/day; it is not a validated individual water prescription. EFSA references include drinks AND food moisture: 2.0 L/day for adult females and 2.5 L/day for adult males at moderate activity and temperature. They do not validate this weight-based equation or this drinking log target.
EFSA references include drinks AND food moisture: 2.0 L/day for adult females and 2.5 L/day for adult males at moderate activity and temperature. They do not validate this weight-based equation or this drinking log target.
The old day is archived and the current local day is loaded in one storage write. On failure, the saved day remains clearly dated; no malformed record is deleted.