BMR Calculator
Calculate your Basal Metabolic Rate (BMR) — the number of calories your body burns at complete rest to keep you alive. The foundation for understanding your energy needs.
What is Basal Metabolic Rate (BMR)?
Your Basal Metabolic Rate is the number of calories your body needs to perform its most basic, life-sustaining functions while at complete rest — breathing, circulating blood, regulating temperature, growing and repairing cells, and keeping your brain and organs working. Even if you stayed in bed all day, your body would still burn this baseline amount of energy. For most people, BMR accounts for 60 to 70% of the total calories they burn each day.
What affects your BMR?
Several factors influence your BMR. Muscle tissue burns more calories at rest than fat, so people with more muscle have a higher BMR. Larger bodies require more energy, so weight and height matter. BMR generally declines with age as muscle mass decreases. Men typically have a higher BMR than women because they tend to carry more muscle. Genetics, hormones and certain medical conditions, such as thyroid disorders, can also raise or lower your metabolic rate.
BMR versus TDEE
BMR is only part of the picture. Your Total Daily Energy Expenditure (TDEE) is your BMR plus the calories you burn through daily movement, exercise and digesting food. To estimate your full daily calorie needs, we multiply your BMR by an activity factor. The table in your results shows what your total needs look like at different activity levels, from sedentary to very active.
How to use your BMR
Knowing your BMR helps you set realistic nutrition goals. It tells you the minimum energy your body needs, which is why eating far below your BMR for long periods is generally discouraged — it can slow your metabolism, reduce muscle and harm health. For weight management, it is better to base your calorie targets on your TDEE and create a moderate deficit or surplus. Building muscle through resistance training is one of the few ways to meaningfully raise your BMR over time.
Frequently Asked Questions
BMR varies widely by age, sex, height, weight and body composition, so there is no single normal value. As a rough guide, many adult women have a BMR between 1,200 and 1,500 calories per day and many adult men between 1,500 and 1,800, but your individual figure depends on your specific characteristics.
Sources & References
- 1.Mifflin MD, St Jeor ST, et al.. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition.
- 2.Harvard Health Publishing. Calorie burning: it's time to rethink your metabolism.
- 3.National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Understanding energy balance and metabolism.
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Medical Disclaimer: This tool is for informational and educational purposes only. Results are not a medical diagnosis. Always consult a qualified healthcare professional for medical advice, diagnosis, or treatment. In an emergency, call your local emergency number or visit the nearest hospital immediately.