BMR Calculator – Estimate Your Basal Metabolic Rate
Calculate your basal metabolic rate with Mifflin-St Jeor and Harris-Benedict.
About the BMR Calculator
What is the BMR Calculator?
A BMR calculator estimates the calories your body burns at complete rest just to stay alive.
Why use this calculator?
BMR is the foundation of any calorie plan because it is usually the largest part of your daily burn — knowing it anchors everything else.
How to use it
- Enter your age, gender, height and weight.
- Read your BMR from several equations.
- Combine it with an activity factor to get daily maintenance calories.
Formula
Mifflin-St Jeor: 10·kg + 6.25·cm − 5·age + (5 or −161).
Equation estimates vary by a few percent. Metabolic testing gives a direct number if you need precision.
Frequently Asked Questions
What is the difference between BMR and RMR?
RMR (resting) is measured under lighter conditions and runs a little higher than true BMR. Both are near-enough for planning.
Can I raise my BMR?
Slightly — more lean muscle and higher body temperatures raise it, but the effect is modest. Activity dominates the daily total.
Is this a medical diagnosis?
No. This tool provides general wellness information only. It is not a substitute for evaluation by a qualified healthcare professional.
Why do results differ from my doctor's measurements?
Clinical measurements use calibrated equipment and professional technique. Home estimates rely on formulas and self-reported values, so small differences are normal.
How often should I recalculate?
Recheck after meaningful changes such as weight gain or loss, a new workout routine, or every few months to track trends over time.
Do these formulas apply to everyone?
Most population formulas are less accurate for athletes, pregnant people, very young children and the elderly. Use them as a general guide.
Is this calculator free to use?
Yes. Every calculator on this site is completely free, with no hidden fees, no subscriptions and no limits on how many times you can use it.
How accurate are the results?
We use standard, widely accepted formulas and calculate in your browser using double-precision arithmetic. Results are rounded for readability, so treat them as reliable estimates rather than a guarantee. Real-world factors can vary the true figure.
Can I add this calculator to my own website?
Yes. Open this calculator page and use the "Add to your website" box in the sidebar to copy a ready-made iframe snippet, then paste it into any HTML page.
Does it work on a phone or tablet?
Yes. The layout is fully responsive, so it works on desktops, laptops, tablets and mobile phones, and every input adapts to touch screens.