💧 Water Intake Calculator for 40kg
How much water should you actually drink? Let's settle this.
Quick answer
At 40kg you should aim for around 1.4 litres of water a day — about 6 glasses (250 ml each).
- Daily target: 1.4 litres
- In glasses (250ml): ~6
- In pints: ~2
- Per hour waking (16h): ~88 ml
In detail: Water Intake Calculator for 40kg
A 40kg body needs roughly 1.4 litres of fluid intake per day — but "fluid intake" includes everything: tea, coffee, soft drinks, and the ~20% of your intake that typically comes from food. Plain water is a subset, not the whole target.
At this bodyweight, over-hydration is a real thing — drinking much more than 1.4L/day of plain water doesn't produce additional benefit and can stress your kidneys if consistent.
Context matters: hot weather, exercise, breastfeeding, or illness can raise the target by 20–50%. The simplest check is urine colour — pale straw is ideal, darker than that suggests you're behind.
What this tool helps with
Your recommended daily water intake in litres
What you can enter
- Your weight (kg): 40
- Activity level: Sedentary
Why this page is useful
How much water should you actually drink? Let's settle this. This page loads fast, gives a direct answer, and then expands with useful context instead of burying the result under filler.