BMR Calculator
Estimate your Basal Metabolic Rate using the Mifflin-St Jeor equation.
✓ Professional standard Uses internationally recognised clinical formulas — WHO, NHS, CDC, the U.S. Navy method and Mifflin-St Jeor — for screening-grade estimates.
BMR Calculator is a free online medical & health tool from Toolinza. Estimate your Basal Metabolic Rate using the Mifflin-St Jeor equation. It runs entirely in your browser — your data is never uploaded — needs no signup, and works on any device. Toolinza offers 293+ free tools used by people across the UK, USA, Canada, Australia, the EU, India, Pakistan, the Middle East and worldwide.
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About the BMR Calculator
Your Basal Metabolic Rate (BMR) is the energy your body burns just to keep you alive at rest — breathing, circulation, keeping your organs running. It is the foundation of your daily calorie needs, and knowing it is the first step to any weight or nutrition plan.
This BMR Calculator uses the Mifflin-St Jeor equation, the formula most trusted by dietitians today, to estimate your resting energy needs from your age, sex, height and weight.
How to use the BMR Calculator
- Select your sex and enter your age.
- Enter your height and weight.
- Choose metric or imperial units.
- Read your estimated BMR in calories per day.
Key features of the BMR Calculator
- Uses the trusted Mifflin-St Jeor equation
- Estimates resting calories burned per day
- Foundation for planning calorie intake
- Metric and imperial units
- Private — calculated in your browser
How the BMR Calculator works
This calculator applies standard, peer-reviewed formulas used by health professionals and public-health bodies worldwide. Depending on the metric, that includes the World Health Organization (WHO) classification, NHS and CDC guidance, the Mifflin-St Jeor equation for metabolic rate, and the U.S. Navy method for body composition. Inputs are converted between metric and imperial units using exact factors so results are consistent whichever system you use.
All calculations are performed in your browser, so the health information you enter is never sent anywhere.
Tips & best practices
- BMR is only your resting burn — add your activity to get TDEE, your true daily calorie need, with the Daily Calorie calculator.
- Never eat below your BMR for long: very low intakes are hard to sustain and can cost you muscle and energy.
- BMR falls slightly as you lose weight, so recalculate every few weeks for an accurate target.
Standards & accuracy
Uses internationally recognised clinical formulas — WHO, NHS, CDC, the U.S. Navy method and Mifflin-St Jeor — for screening-grade estimates.
Important: these tools provide screening-grade estimates for general information and education only. They are not a medical diagnosis and do not replace professional advice. Always consult a qualified healthcare provider before making health decisions.
Who uses the BMR Calculator?
- Understanding your baseline calorie needs
- Building a weight-loss or gain plan
- A starting point before working out TDEE
- Nutrition education and coaching
Privacy & security
The BMR Calculator runs entirely inside your web browser. Your data — whether that is a file, figures or text — is processed on your own device and is never uploaded to a server, stored or shared. There is no signup and no account, so you can use it as often as you like while keeping full control of your information. This makes it a safe choice even for confidential and sensitive work.
Why choose Toolinza?
- 100% free — no hidden charges, watermarks or usage caps.
- Private & secure — your data stays on your device.
- Standards-compliant — accurate results suitable for the UK, USA, Canada, Australia, EU, India, Pakistan, the Middle East and worldwide.
- Works everywhere — desktop, tablet and mobile.
Frequently asked questions
Basal Metabolic Rate is the number of calories your body burns at complete rest to maintain vital functions. It is usually the largest part of your daily calorie burn.
It uses the Mifflin-St Jeor equation, which is widely regarded as one of the most accurate BMR formulas for the general population.
BMR is your resting burn, while TDEE adds the calories you burn through daily activity and exercise. TDEE is your true maintenance calorie need.
Yes. The BMR Calculator is completely free with no signup, no watermarks and no usage limits. Toolinza is supported by unobtrusive advertising so every tool stays free.
Absolutely. This tool runs entirely in your browser — your data and files are never uploaded to any server, so everything stays private on your own device.
No. The BMR Calculator works instantly in any modern web browser on desktop, tablet and mobile — Windows, macOS, Linux, Android and iOS.