HEALTH CALCULATOR
BMR Calculator
Estimate your basal metabolic rate (BMR) and the number of calories your body needs each day at complete rest.
What Is BMR?
Basal metabolic rate, or BMR, is an estimate of the amount of energy your body uses while at rest to maintain essential functions such as breathing, circulation, and maintaining body temperature.
BMR does not represent the total number of calories you burn during an entire day. Daily calorie needs also depend on physical activity, exercise, and other factors.
How Is BMR Calculated?
This calculator uses the Mifflin-St Jeor equation, a commonly used formula for estimating BMR from body weight, height, age, and sex.
For men, the formula is:
BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
For women, the formula is:
BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
What Factors Affect BMR?
Several characteristics can influence a person's basal metabolic rate, including:
- Age
- Body weight
- Height
- Sex
- Body composition
- Other individual factors
Because BMR is an estimate, the result should be treated as a useful starting point rather than an exact measurement of your metabolism.
BMR vs. TDEE
BMR and total daily energy expenditure (TDEE) are different measurements.
BMR estimates the energy your body needs at rest. TDEE estimates the total energy you use throughout the day, including normal movement, exercise, and other activities.
A person's daily calorie needs are therefore generally higher than their BMR.
BMR Calculator Example
Consider a 30-year-old man who is 175 cm tall and weighs 70 kg. Using the Mifflin-St Jeor equation:
BMR = 10 × 70 + 6.25 × 175 − 5 × 30 + 5
This produces an estimated BMR of approximately 1,674 calories per day.
This means his estimated resting energy requirement is around 1,674 calories per day before accounting for normal daily activity.
How to Use Your BMR
BMR can be used as a starting point when estimating daily calorie requirements. To estimate total daily calorie needs, BMR can be combined with an activity level.
Our Calorie Calculator can help estimate daily calorie needs based on activity level.
Frequently Asked Questions
What does BMR stand for?
BMR stands for basal metabolic rate. It estimates the amount of energy your body uses at rest to maintain essential functions.
What is a normal BMR?
There is no single normal BMR. BMR varies between individuals based on factors such as age, sex, height, weight, and body composition.
Is BMR the same as daily calorie needs?
No. BMR estimates calories used at rest, while total daily calorie needs also include physical activity and other daily energy expenditure.
Which BMR formula does this calculator use?
This calculator uses the Mifflin-St Jeor equation to estimate BMR.
Can BMR change over time?
Yes. BMR can change as factors such as age, body weight, and body composition change.
Is a BMR calculator accurate?
A BMR calculator provides an estimate rather than a direct measurement of metabolism. Individual results can vary.