Want to estimate how many calories your body needs at rest? Our free BMR Calculator helps you calculate your Basal Metabolic Rate (BMR) using your age, gender, height, and weight.
Choose your preferred units, enter your details, and the calculator will give you an estimated number of calories your body may use each day at rest. You can use this number as a starting point when planning your daily calorie intake, weight management, or fitness goals.
This calculator uses the Mifflin-St Jeor equation, a commonly used formula for estimating resting energy needs. Your actual calorie needs can be different depending on your activity level, body composition, health, and other factors.
What Is a BMR Calculator?
BMR stands for Basal Metabolic Rate. It is an estimate of how many calories your body uses to support basic functions while at rest, such as breathing, circulation, and maintaining normal body functions.
Our BMR Calculator uses your age, gender, height, and weight to provide an estimated daily BMR. It supports both metric and imperial units, so you can enter your measurements in the format you normally use.
How to Use the BMR Calculator
Using the calculator is simple:
- Choose Metric or Imperial units.
- Enter your age.
- Enter your weight.
- Enter your height.
- Select Male or Female.
- Click Calculate.
The calculator will show your estimated BMR in calories per day.
How Is BMR Calculated?
This calculator uses the Mifflin-St Jeor equation, which uses age, weight, height, and sex to estimate resting energy needs.
For men:
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
For women:
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
If you use pounds and inches, the calculator first converts your measurements to kilograms and centimeters before applying the formula.
What Does Your BMR Number Mean?
Your BMR is an estimate of the energy your body needs at rest. It is not the number of calories you necessarily need to eat each day.
Your actual daily calorie needs are usually higher because normal activities, walking, work, exercise, and digestion all require additional energy.
For example, a BMR of 1,600 kcal/day does not mean you should automatically eat exactly 1,600 calories every day. It is better viewed as a starting point for understanding your estimated energy needs.
BMR vs. Daily Calorie Needs
BMR and daily calorie needs are not the same thing.
BMR estimates energy used at rest, while your total daily energy expenditure also includes the energy used for physical activity and other normal body processes.
This is why two people with a similar BMR can still have very different daily calorie requirements depending on their activity and lifestyle.
Is BMR the Same for Everyone?
No. BMR varies from person to person. Age, body weight, height, and sex are among the factors included in the Mifflin-St Jeor calculation, while individual differences in body composition and other factors can also affect actual energy expenditure.
The result from this calculator should therefore be treated as an estimate rather than an exact measurement.
Frequently Asked Questions
What does BMR stand for?
BMR stands for Basal Metabolic Rate. It refers to the estimated amount of energy the body uses at rest to support basic functions.
Is BMR the number of calories I should eat?
Not necessarily. BMR is only an estimate of resting energy needs. Your total daily calorie requirement is generally higher because it also includes activity and other energy expenditure.
Does gender affect the BMR calculation?
Yes. The Mifflin-St Jeor equation uses a different constant for males and females, which is why the calculator asks you to select your gender.
Can I use pounds and inches?
Yes. Select Imperial units and enter your weight in pounds and height in inches.
Can I use kilograms and centimeters?
Yes. Select Metric units and enter your weight in kilograms and height in centimeters.
Is a BMR calculator accurate?
A BMR calculator provides an estimate rather than a direct measurement. Individual energy needs can vary, so the result should not be treated as an exact number.
Disclaimer: This BMR Calculator is intended for general informational purposes. It provides an estimate and should not be used as a substitute for professional medical or nutrition advice, particularly if you have a medical condition or specific dietary needs.