HEALTH CALCULATOR
BMR Calculator
Estimate your basal metabolic rate (BMR), the approximate number of calories your body uses at rest to support essential functions. See how estimated daily calorie needs change across common activity levels.
Build Your BMR Profile
Enter your information to estimate resting calorie needs.
Measurement system
Personal information
Estimated Daily Calories by Activity
BMR multiplied by common activity factors gives an estimate of total daily energy needs.
Activity Comparison
How estimated daily needs rise above resting energy use.
Energy Breakdown
A quick reference for the calculated BMR and activity estimates.
BMR Activity Table
Estimated calories per day using the selected BMR.
| Activity | Multiplier | Description | Calories / day |
|---|---|---|---|
| Sedentary | 1.200× | Little or no exercise | 1,979 |
| Lightly active | 1.375× | Light exercise 1–3 days/week | 2,267 |
| Moderately active | 1.550× | Moderate exercise 3–5 days/week | 2,556 |
| Very active | 1.725× | Hard exercise 6–7 days/week | 2,844 |
| Extra active | 1.900× | Very hard exercise or physical work | 3,133 |
What Is BMR?
Basal metabolic rate, or BMR, estimates the energy your body uses at rest to maintain essential functions such as breathing, circulation, and body temperature. It is expressed in calories per day.
BMR differs from the total calories you use during a normal day. Daily energy expenditure also includes movement, exercise, digestion, and other activities.
How Is BMR Calculated?
This calculator uses the Mifflin-St Jeor equation. It uses body weight, height, age, and sex to estimate resting energy needs.
For men:
For women:
When you enter US units, height and weight are converted to metric units before the equation is applied. The displayed BMR is rounded to the nearest whole calorie.
BMR vs. Daily Calorie Needs
BMR represents estimated resting energy use. Including normal activity produces a higher estimate of daily calorie needs, which is why this calculator shows activity-based estimates alongside the BMR result.
| Activity level | Typical description |
|---|---|
| Sedentary | Little or no exercise |
| Lightly active | Light exercise 1–3 days per week |
| Moderately active | Moderate exercise 3–5 days per week |
| Very active | Hard exercise 6–7 days per week |
| Extra active | Very hard exercise or physical work |
What Factors Affect BMR?
The equation uses age, sex, height, and body weight. Actual energy requirements can also vary with body composition and other individual characteristics that a simple equation cannot fully capture.
BMR Calculator Example
Consider a 30-year-old man who is 175 cm tall and weighs 70 kg. Using the Mifflin-St Jeor equation:
The estimated BMR is approximately 1,674 calories per day.
How to Use Your BMR
BMR is a starting point for estimating overall daily calorie needs. Add an activity estimate to account for movement and exercise, or use a calculator designed for total daily energy expenditure.
The Calorie Calculator estimates daily calorie needs using an activity level. The TDEE Calculator provides another estimate of total daily energy expenditure. You can also use the BMI Calculator to calculate body mass index or the Body Fat Calculator for an estimate of body-fat percentage.
How Accurate Is a BMR Calculator?
This calculator estimates BMR with a mathematical equation rather than measuring metabolism directly. Actual resting energy expenditure can differ between individuals.
Treat the result as a reference, not an exact calorie requirement. For individualized nutrition guidance, discuss your goals and circumstances with a qualified healthcare or nutrition professional.
Frequently Asked Questions
What does BMR stand for?
BMR stands for basal metabolic rate. It estimates the energy your body uses at rest to support essential functions.
What is a normal BMR?
There is no single normal BMR. Estimated resting energy needs vary with factors such as age, sex, height, weight, and body composition.
Is BMR the same as daily calorie needs?
No. BMR estimates resting energy use. Total daily calorie needs also include movement, exercise, digestion, and other activities.
Which BMR formula does this calculator use?
This calculator uses the Mifflin-St Jeor equation to estimate BMR from age, sex, height, and body weight.
Can BMR change over time?
Yes. Changes in age, body weight, and body composition can affect estimated resting energy needs.
Does BMR include exercise?
No. Exercise and everyday movement are considered separately when estimating total daily energy expenditure.