BMR calculator
What is your basal metabolic rate?
Your basal metabolic rate (BMR) is the energy your body burns at complete rest — for breathing, your heartbeat, your organs. Work it out with the Mifflin-St Jeor formula and see right away what total expenditure it becomes at each activity level.
Your basal metabolic rate
That's what your body burns at complete rest — before daily movement and training.
| Activity level | Factor | Total expenditure |
|---|---|---|
| Sedentary, hardly any training | 1.2 | – kcal |
| Lightly active | 1.375 | – kcal |
| Moderately active | 1.55 | – kcal |
| Very active | 1.725 | – kcal |
| Extremely active | 1.9 | – kcal |
And what do you do with that number now?
The BMR is the baseline — plans are built on total expenditure plus a goal. Myron keeps recalculating both from your real data and tracks your food by voice.
How the BMR calculator works
The basis is the Mifflin-St Jeor formula: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), plus 5 for men or minus 161 for women. In comparison studies it estimates resting expenditure more reliably than the older Harris-Benedict formula — which is why the Myron coach and the calorie calculator use it too.
For your calorie target, what matters is your total expenditure: BMR times activity factor (PAL), see the table in the result. How that becomes a target for weight loss or muscle gain is covered under methodology & data sources.
Frequently asked questions
What is the basal metabolic rate?
The energy your body burns at complete rest — for breathing, heartbeat, brain and organs. For most people it accounts for 60–70% of daily expenditure and depends mainly on body weight, height, age and sex.
What is the difference between BMR and total expenditure?
The BMR is what you burn at rest. Total daily energy expenditure (TDEE) adds daily movement, work and training via the activity factor (PAL) — it is the number calorie targets are based on.
Should I eat less than my BMR?
Not advisable long-term: very large deficits cost a disproportionate amount of muscle mass and performance and are hard to sustain. A moderate deficit below your total expenditure — not below your BMR — gets you there more sustainably.
Can I raise my basal metabolic rate?
Meaningfully mostly through more muscle mass — strength training plus enough protein. The oft-cited metabolism tricks (spicy food, cold water, special foods) amount to a few calories per day.
How accurate is the calculation?
Formulas estimate — real deviations of ±10% are normal because metabolism is individual. The result is a good starting point; the truth shows in your weight trend over 2–3 weeks. That's why the Myron app keeps recalculating your actual expenditure from your history.
Formula: Mifflin MD, St Jeor ST et al. (1990): A new predictive equation for resting energy expenditure in healthy individuals — more under methodology & data sources. More to look up: calorie tables for German foods · exercise directory.