Your body relies on calories — a unit of energy — at all times, including when you’re at rest.
Your basal metabolic rate (BMR) is the number of
- heart rate and blood flow
- metabolism (digestion and nutrient absorption)
- cell function, growth, and repair
Keep in mind that your BMR includes only the energy (calories) necessary for basic, life-sustaining functions. It does not include additional calories needed for daily activities, such as walking, moving, and exercising.
If you’re wondering how to calculate your BMR, this article will tell you exactly how.
How to use this calculator
This calculator uses your age, size, sex, and activity level to estimate the number of calories you should eat per day to maintain your weight.
If you’re trying to gain or lose weight, you can adjust this number to align with your goal.
Keep in mind that this tool provides only general guidance. Your activity level and many other factors influence your daily calorie needs. Thus, this calculator will likely provide a number that’s close to your calorie needs, but it’s not a perfect tool.
A doctor or dietitian can offer more individualized advice on your ideal calorie intake, depending on your health status and goals.
Note: This calculator calculates your total daily energy expenditure (TDEE), which is the total number of calories your body burns in a day, including movement and physical activity.
Your TDEE includes your BMR and an activity factor based on your activity level.
Your BMR can be calculated using
If you’re looking for the most accurate number, then you’ll want to visit a clinic that offers direct or indirect calorimetry:
- Direct calorimetry is the most accurate method. It involves spending time in a tightly controlled room, known as a calorimeter, with little to no movement. However, it’s typically used only in research settings and is difficult to access.
- Indirect calorimetry involves using an in-office device that measures the exchange of oxygen and carbon dioxide in your body.
However, since most people do not have access to these devices, researchers have developed more convenient methods of calculating BMR. In particular, the
Technically, this equation calculates your resting metabolic rate (RMR), which is slightly different from BMR. RMR determines the calories you burn at rest with minimal movement. BMR is more restrictive and measures calories with zero movement in the day.
However, BMR and RMR are often used interchangeably, and calculating your RMR should get you a pretty close estimate of your BMR.
To calculate your BMR/RMR using the
- Males: 10 × weight (in kilograms) + 6.25 × height (in centimeters) – 5 × age (in years) + 5
- Females: 10 × weight (in kilograms) + 6.25 × height (in centimeters) – 5 × age (in years) – 161
For example, a 35-year-old, 200-pound (90.7-kg), 6-foot (183-cm) male would have a BMR/RMR of 1,882. At rest, he’ll burn around 1,882 calories in a day.
A 35-year-old female who weighs 150 pounds (68 kg) and is 5 feet 7 inches (170 cm) tall will burn around 1,409 calories per day at rest.
While it’s useful as a starting point, your BMR is not the number of calories your body needs in a day. It’s only the number of calories your body needs at rest.
To calculate your TDEE (the total calories you need each day), you need to multiply your BMR by an activity factor.
A note on sex and gender
You’ll notice that the language used to share stats and other data is pretty binary: “male” and “female.”
We recognize that these terms don’t encompass all identities and experiences. However, specificity is key when reporting on research participants and clinical findings, so we use the same language that the studies we cite use.
We encourage you to talk with a qualified healthcare professional if you need support navigating how the information in this article may apply to you.
While useful, BMR calculators are not 100% accurate.
Although the Mifflin-St. Jeor equation is known as one of the most accurate calculators, its result can be off by
Also, without including your activity level in the equation, you’re not actually calculating your daily calorie needs. Eating only enough calories to match your BMR is not safe or healthy.
Finally, while knowing your BMR can provide some insight, it does not paint a full picture of your health. For instance, your muscle-to-fat mass, underlying health conditions, hormone levels, and other metrics are also important aspects of health.
Trying to “do it right” when it comes to nutrition may feel tempting, but it can backfire.
If you are preoccupied with food or your weight, feel guilt surrounding your food choices, or routinely engage in restrictive diets, consider reaching out for support. These behaviors may indicate a disordered relationship with food or an eating disorder.
Disordered eating and eating disorders can affect anyone, regardless of gender identity, race, age, body size, socioeconomic status, or other identities.
They can be caused by any combination of biological, social, cultural, and environmental factors — not just by exposure to diet culture.
Feel empowered to talk with a qualified healthcare professional, such as a registered dietitian, if you’re struggling.
You can also chat, call, or text anonymously with trained volunteers at the National Eating Disorders Association helpline for free or explore the organization’s free and low cost resources.
Your BMR tells you how many calories you burn at rest. It’s an indicator of your metabolic activity before considering daily movement.
However, since we do not use BMR to calculate our total daily calorie needs, it’s really only the first step of a larger equation.
To calculate your TDEE, you’ll need to add an activity factor to the equation:
- 1.2: sedentary (little to no exercise)
- 1.375: lightly active (light exercise 1 to 3 days per week)
- 1.55: moderately active (moderate exercise 6 to 7 days per week)
- 1.725: very active (hard exercise every day, or exercising twice a day)
- 1.9: extra active (very hard exercise, training, or a physical job)
Then, you can calculate your TDEE using this equation:
- TDEE = BMR x activity factor
This number will give you a general idea of how many calories your body needs per day to maintain your current weight.
Does a lower vs. higher BMR mean anything about your health?
A higher BMR can indicate that you have a larger body, more muscle mass, genetics that favor a faster metabolism, or, potentially, an underlying medical condition such as hyperthyroidism.
A higher or lower BMR does not necessarily mean you’re healthier or less healthy than someone else.
However, if you’re having difficulty losing or gaining weight despite changes in your eating patterns and physical activity, you may want to check in with a healthcare professional to be screened for medical conditions that may affect metabolism, such as thyroid issues and diabetes.
Your BMR is based on a variety of
- body size (height and weight)
- body composition (fat mass and muscle mass)
- medical conditions
While you can change some of these, such as your body composition to some degree, there are others that you cannot change, including genetics, height, and age.
Also, following a very low calorie diet
“BMR” stands for “basal metabolic rate” — the estimated number of calories your body burns when you’re not moving at all.
Since you may not have access to a clinic that offers direct or indirect calorimetry, you can easily estimate your BMR using the Mifflin-St. Jeor equation.
But keep in mind that this number does not tell you how many calories you need to eat in a day — you need to eat more than this to stay healthy. To figure out how many calories you need per day, you’ll need to calculate your BMR and multiply it by an activity factor.
Consider discussing your energy needs with a doctor or registered dietitian if you have more questions about how many calories you need.
If you’re looking to increase your BMR, you can try to gain muscle and make sure you’re eating enough calories each day. However, your BMR is also based on some factors that you cannot change, such as your height, age, and genetics.