Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Daily Water Intake Calculator
Estimate how much water you should drink each day based on body weight and activity level — a far better starting point than the generic "8 glasses a day" rule, which has no scientific basis. The output is total fluid in litres, including water from food (typically about 20% of daily intake) and beverages other than plain water.
BMR / TDEE Calculator
Estimate your daily calorie needs using the revised Harris-Benedict equation, then adjust for activity to get your Total Daily Energy Expenditure (TDEE) — the rough number of calories you burn in 24 hours when you eat a maintenance diet. Enter your weight in kilograms, height in centimetres, age, biological sex, and an activity multiplier (sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725, extremely active 1.9). The result is what most nutrition guides call your "maintenance calories" — a starting point for designing a deficit (to lose weight), a surplus (to gain muscle), or a recomposition plan.
Key differences
| Daily Water Intake Calculator | BMR / TDEE Calculator | |
|---|---|---|
| Category | Health | Health |
| Inputs required | 2 | 5 |
| Result | Daily Water Intake (liters) | Daily Calorie Needs (calories) |
| What it does | Estimate how much water you should drink each day based on body weight and activity level — a far better starting point than the generic "8 glasses a day" rule, which has no scientific basis. The output is total fluid in litres, including water from food (typically about 20% of daily intake) and beverages other than plain water. | Estimate your daily calorie needs using the revised Harris-Benedict equation, then adjust for activity to get your Total Daily Energy Expenditure (TDEE) — the rough number of calories you burn in 24 hours when you eat a maintenance diet. Enter your weight in kilograms, height in centimetres, age, biological sex, and an activity multiplier (sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725, extremely active 1.9). The result is what most nutrition guides call your "maintenance calories" — a starting point for designing a deficit (to lose weight), a surplus (to gain muscle), or a recomposition plan. |