Water Intake Calculator
Calculate how much water you should drink daily based on your weight, activity level and climate. Shows glasses, litres and bottles
Daily Water Intake
2.7
litres per day
2700 ml
Glasses (250ml)
11
Cups (240ml)
11
Bottles (500ml)
5
💧 Hourly Drinking Schedule
Drink about 1 glass every hour during the day
(338 ml per reminder)
Example Schedule:
7am, 9am, 11am, 1pm, 3pm, 5pm, 7pm, 9pm
💡 Tips for Staying Hydrated
- • Drink water before you feel thirsty
- • Keep a water bottle with you throughout the day
- • Increase intake on hot days and during exercise
- • Herbal tea, coffee, and water-rich foods count toward hydration
- • Urine colour is a good indicator: pale = well hydrated, dark = need more water
📋 Individual Needs Vary
This is a general guideline. Actual needs depend on climate, altitude, diet, and individual factors. Listen to your body and adjust accordingly.
How Much Water Do You Actually Need?
The 'eight 8-oz glasses' (8x8) rule = 64 oz = 1.9 L. NHS recommendation: 6-8 cups of fluids daily, mostly water. EFSA: 2.0 L/day women, 2.5 L/day men - including ALL fluid sources (food contains 20% of daily water need, beverages 80%). Activity, climate, and body size shift these baselines significantly.
Multiply by activity: sedentary office work in temperate climate = baseline. Add 0.5-1 L for moderate exercise. Add 1-2 L for heavy exercise or hot climate. Body weight: roughly 30-40 ml/kg body weight gives a personalised baseline. So a 70 kg person needs about 2.1-2.8 L/day. Heavy training, hot weather, or pregnancy increase needs.
Daily Water Intake by Body Weight
| Weight | Sedentary | Moderately active | Heavy training |
|---|---|---|---|
| 50 kg (110 lb) | 1.5 L | 2.0 L | 3.0 L |
| 60 kg (132 lb) | 1.8 L | 2.4 L | 3.5 L |
| 70 kg (154 lb) | 2.1 L | 2.8 L | 4.0 L |
| 80 kg (176 lb) | 2.4 L | 3.2 L | 4.5 L |
| 90 kg (198 lb) | 2.7 L | 3.6 L | 5.0 L |
| 100 kg (220 lb) | 3.0 L | 4.0 L | 5.5 L |
Frequently Asked Questions
Does coffee count toward water intake?
Yes. Despite caffeine's mild diuretic effect, coffee and tea contribute net positive to hydration. The diuretic effect is overstated - most studies show only modest urine increase with normal caffeine intake. Treat 1 cup of coffee as roughly 1 cup of water for hydration purposes.
Can you drink too much water?
Yes - hyponatremia (low blood sodium) from drinking 4-5 L+ in a short period without electrolyte replacement. Most common in marathon runners and military trainees. For sedentary or moderate activity, drinking to thirst is sufficient. Forcing 'extra' water beyond thirst rarely helps.
Related Tools
TDEE Calculator
Calculate your Total Daily Energy Expenditure using the Mifflin-St Jeor equation. Get calorie targets for weight loss, maintenance and gain
Ml to Cups Converter
Convert millilitres to cups with our free tool. Handy for converting metric recipes to cup measurements.
Ml to Fl Oz Converter
Convert millilitres to fluid ounces easily. Free ml to fl oz converter for cooking recipes.