BMI calculator
A quick adult screening estimate based on height and weight.
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Know your numbers.
Use them thoughtfully.
Five simple calculators to help you plan everyday nutrition and fitness habits. Your entries stay in your browser and are not saved.
Free wellness estimates5 practical tools
Clear results, metric units and no account required.
Calculate your starting point
Small estimates.
Clearer choices.
Complete only the calculator you need. Results are generated instantly on your device.
Calorie / TDEE calculator
Estimate maintenance energy using the Mifflin–St Jeor equation and an activity factor.
Protein calculator
A practical daily range estimate based on body weight, movement and goal.
Macro calculator
Turn a daily calorie target into a simple protein, carbohydrate and fat split.
Water intake calculator
A simple hydration planning estimate based mainly on body weight and daily activity.
Please keep in mind
Useful for planning.
Not medical advice.
These calculators provide general adult wellness estimates. They cannot account for medical conditions, pregnancy, medications, body composition, climate or individual clinical needs. Do not use them to diagnose or treat a condition.
If you are under 18, pregnant, managing a health condition, have a history of disordered eating, or need a therapeutic diet, speak with a qualified healthcare professional or registered dietitian.
Formula notes and reference sources
- BMI categories and adult healthy range follow the CDC adult BMI guidance.
- Resting energy uses the Mifflin–St Jeor equation, then applies an activity estimate.
- Protein estimates stay within the broad active-adult range discussed by the NIH Office of Dietary Supplements.
- Macro splits remain within accepted adult ranges described in U.S. dietary guidance.
- Hydration needs vary widely; the National Academies notes that activity and environment can materially change requirements.
Coming in the next phase