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Water Intake by Weight Calculator
Quick answer
If weight is 70 kg and target is 35 ml/kg, the water target is 2.45 L/day.
Water target: Litres per day = weight (kg) × ml per kg ÷ 1000.
Enter your values
30 kg200 kg
kg
20 ml/kg50 ml/kg
ml/kg
Water target
2.45L/day
Calculated directly from the values you entered above.
You enter Weight 70 kg, Target 35 ml/kg. You get Water target 2.45 L/day.
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About the Water Intake by Weight Calculator
How much water you need depends on your body size, activity, climate and health. A common rule of thumb is 30 to 40 ml per kilogram of body weight per day. Enter your weight and the target in ml per kg to see litres per day.
This estimate counts all fluids and water-rich foods, not just plain water.
Water target
Litres per day = weight (kg) × ml per kg ÷ 1000
Things to keep in mind
- Needs rise in hot weather, with exercise, and during illness such as fever or diarrhoea.
- Pale yellow urine is a simple sign of good hydration.
- People with kidney, heart or other conditions should follow their doctor's advice on fluids.
See how the result changes
Each table re-runs this calculator with one value changed and everything else left as it is.
Water target by weight
If weight goes from 70 kg to 105 kg, water target changes from 2.45 L/day to 3.68 L/day (+50%).
| Weight | Water target |
|---|---|
| 35 kg | 1.23 L/day |
| 52.5 kg | 1.84 L/day |
| 70 kgstart | 2.45 L/day |
| 105 kg | 3.68 L/day |
| 140 kg | 4.9 L/day |
Water target by target
If target goes from 35 ml/kg to 50 ml/kg, water target changes from 2.45 L/day to 3.5 L/day (+43%).
| Target | Water target |
|---|---|
| 20 ml/kg | 1.4 L/day |
| 26 ml/kg | 1.82 L/day |
| 35 ml/kgstart | 2.45 L/day |
| 50 ml/kg | 3.5 L/day |
HEALTH & FITNESS GUIDE
A quick guide to Water Intake by Weight
Use it to get an accurate water target in seconds — free, with no sign-up.
Instant results
See your water target the moment you enter your numbers.
Free, no sign-up
Every calculator here is free to use, with no account required.
Accurate & transparent
The same standard formula runs on our server for every calculation.
How to Use the Water Intake by Weight Calculator
1
Enter Weight
Provide your weight, in kg.
2
Enter Target
Provide your target, in ml/kg.
3
View Your Results
Get your water target instantly, calculated on our server.
What is Water Intake by Weight?
This health & fitness tool works out your water target instantly, so you don't have to do the math by hand.
“One quick calculation, so you always know your water target before you decide.”
What Affects Your Water target
Your water target depends on the values below.
Weight
Changing your weight changes your water target.
Target
Changing your target changes your water target. Typically between 20 and 50 ml/kg.
Example Result
Here's what you can expect from a water intake by weight calculation:
- Weight
- 70 kg
- Target
- 35 ml/kg
- Water target
- 2.45 L/day
Frequently Asked Questions
- How does weight affect water target?
- If weight goes from 70 kg to 105 kg, water target changes from 2.45 L/day to 3.68 L/day (+50%).
- How does target affect water target?
- If target goes from 35 ml/kg to 50 ml/kg, water target changes from 2.45 L/day to 3.5 L/day (+43%).
- How to calculate water intake by weight?
- Fill in weight and target in the Water Intake by Weight Calculator above and your water target is calculated instantly. Change any value to see how the result responds.
- What does an example water intake by weight calculation look like?
- If weight is 70 kg and target is 35 ml/kg, the water target is 2.45 L/day.
- Is this calculator free to use?
- Yes — every calculator on this site is completely free, with no sign-up or account required.
- How accurate is this calculator?
- It uses the standard formula and calculates on our server for every request, so results are precise for the values you enter.
- Is my data saved anywhere?
- No. Nothing you enter is stored or sent anywhere unless you choose to share a link with your values included.
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