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BMR Calculator
Basal Metabolic Rate — the calories your body burns at complete rest. The foundation for all energy calculations.
Your details
This is approximately average for a 35-year-old male.
What this means
Your body burns approximately 1,643 calories per day just to maintain basic functions: breathing, circulation, cell repair, and temperature regulation. This is before any movement, digestion, or exercise. BMR typically accounts for about 60–70% of your total daily energy expenditure.
What to consider
Your BMR is the starting point, not the full picture. To understand how many calories you actually burn in a day, use the TDEE Calculator which adjusts for your activity level. The Macronutrient Calculator then helps you set protein, carb, and fat targets based on that number.
Medications that may affect your result
Thyroid medications (levothyroxine, methimazole) directly affect metabolic rate. Hypothyroidism lowers BMR; hyperthyroidism raises it. If you are on thyroid medication, your actual BMR may differ from this estimate.
Corticosteroids (prednisone, dexamethasone) can alter body composition over time, which indirectly affects BMR through changes in lean mass and fat distribution.
Your baseline may differ from the general population. Discuss with your healthcare provider.
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About this tool
Formula
Mifflin-St Jeor equation (1990), the most validated for general population use.
Male: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
Female: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Known Limitations
Validated predominantly on White populations. Accuracy varies across ethnicities. Less accurate for people with thyroid conditions, as hypo/hyperthyroidism significantly affects metabolic rate independent of body composition. May underestimate BMR in very muscular individuals and overestimate in those with higher body fat percentages at the same weight.
Sources
Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990.
Educational tool only. Not for diagnostic purposes. Consult a healthcare provider for medical decisions.