BMR & Calorie Calculator
Estimate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the highly accurate Mifflin-St Jeor equation.
BMR Calculator
Calculate your daily calories
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Calorie Adjustments
Calories to maintain current weight.
Approx. 1 lb loss per week.
Approx. 1 lb gain per week.
What is Basal Metabolic Rate (BMR)?
Your Basal Metabolic Rate (BMR) is the total number of calories that your body needs to perform basic, life-sustaining functions while at complete rest. These functions include breathing, circulating blood, cellular growth, regulating body temperature, and neurological activity. BMR accounts for about 60-75% of your total daily energy expenditure.
The Mifflin-St Jeor Equation
Introduced in 1990, the Mifflin-St Jeor equation is widely considered by health professionals and the Academy of Nutrition and Dietetics to be the most accurate predictive equation for calculating BMR in non-clinical settings. The formula is:
- Male: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5
- Female: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161
Total Daily Energy Expenditure (TDEE)
Your TDEE is your BMR multiplied by an activity factor that represents your daily physical movement. If your goal is weight loss, you generally need to consume fewer calories than your TDEE. Conversely, to gain muscle or weight, a caloric surplus is required.
- Sedentary: BMR × 1.2
- Lightly active: BMR × 1.375
- Moderately active: BMR × 1.55
- Very active: BMR × 1.725
- Extra active: BMR × 1.9
Frequently Asked Questions
How accurate is the BMR calculator?
The Mifflin-St Jeor equation is highly accurate for most individuals, though it may overestimate calories slightly in people with obesity, as it does not account for lean body mass specifically.
How many calories should I eat to lose weight?
A common approach is a 500-calorie deficit per day from your TDEE, which theoretically yields about 1 pound of weight loss per week. However, individual metabolism varies.
Is BMR the same as RMR?
Resting Metabolic Rate (RMR) is very similar but slightly less restrictive than BMR. BMR requires strict fasting and rest, while RMR can be measured under less rigorous resting conditions.
Can I increase my BMR?
Yes. Muscle tissue burns more calories at rest than fat tissue. Strength training to increase lean muscle mass will incrementally raise your BMR over time.
Does BMR decrease with age?
Yes, BMR naturally declines with age. This is primarily due to the loss of muscle mass (sarcopenia) and hormonal changes as we grow older.
Medical Disclaimer: This calculator is for informational and educational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider. Read full disclaimer →