BMR Calculator
Estimate resting calorie burn with Mifflin-St Jeor and Harris–Benedict equations.
How to Use the BMR Calculator
Enter your gender, age, weight, height, and unit system, then select Calculate BMR. The tool converts imperial measurements and applies two leading formulas to estimate how many calories your body burns at rest.
Results include a primary value plus a breakdown of the Mifflin-St Jeor and Harris–Benedict outputs so you can see how each method differs. Reset the inputs to test alternative body compositions or goal weights.
BMR Equations Explained
The calculator primarily uses the Mifflin-St Jeor formula: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + s, where s equals +5 for men and −161 for women. This equation is widely validated and recommended by dietitians.
For additional context, it also displays the revised Harris–Benedict formula, which historically guided calorie planning. Comparing the two numbers highlights how different assumptions affect resting energy estimates.
Using BMR in Your Wellness Plan
Basal metabolic rate is the foundation for weight loss, maintenance, or muscle gain strategies. Pair the result with activity multipliers to calculate maintenance calories or to design a calorie deficit.
Remember that illness, hormonal conditions, and lean body mass influence BMR. Recalculate periodically and speak with a healthcare professional or registered dietitian for personalized nutrition advice.
Frequently Asked Questions
Which BMR formula is most accurate?
The Mifflin-St Jeor equation provides the closest estimates for most adults, so it powers the main result. The Harris-Benedict update is shown for comparison.
Should I enter weight in pounds or kilograms?
Choose your preferred unit system from the dropdown. The calculator automatically converts imperial measurements to metric before running the formulas.
How do I use BMR to set calorie goals?
Start with your BMR to understand calories burned at rest. Multiply by an activity factor or use the Calorie Needs Calculator to estimate total daily energy expenditure.