How Calculadora de TMB Works
A BMR Calculator (Basal Metabolic Rate) is a biological utility used to estimate the number of calories your body needs to maintain basic life functions while at rest. This includes vital processes such as breathing, blood circulation, cell production, and temperature regulation. Understanding your BMR is the foundation for creating an accurate Weight Management Strategy or Fitness Plan.
The analysis engine calculates your metabolic baseline through a physiological pipeline:
- Metric Input Alignment: The tool captures your Gender, Age, Height, and Weight, normalizing them into the metric system.
- Equation Selection: The engine applies the Mifflin-St Jeor Equation (standard for modern metabolism) or the Harris-Benedict Equation (the historical standard).
- The Formula Execution:
- Men:
BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5 - Women:
BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161
- Men:
- Resting State Isolation: Unlike "Total Daily Energy Expenditure" (TDEE), BMR assumes zero physical activity—simulating the body's energy use while sleeping or in a fasted state.
- Reactive Projection: As you toggle between equations or adjust your age, the tool updates your "Daily Caloric Floor" in real-time.
The History of BMR and the Harris-Benedict Study
The study of metabolic rates began in the early 20th century as nutritionists sought to understand human energy requirements.
In 1919, James Arthur Harris and Francis Gano Benedict published a landmark study titled A Biometric Study of Basal Metabolism in Man. They measured the gas exchange of healthy adults to define for the first time how energy expenditure correlates with biological metrics. While their formula was the gold standard for decades, it was updated in 1990 by Mifflin and St Jeor, whose revised formula is more accurate for Modern Lifestyles and Body Compositions. Today, BMR Calculations are used in clinical nutrition and metabolic health research.
Technical Comparison: BMR Equations
Understanding which formula to use depends on your goal for Nutritional Accuracy.
| Equation | Mifflin-St Jeor (2005) | Harris-Benedict (1919) | Katch-McArdle |
|---|---|---|---|
| Logic | Modern, leaner populations | Historical Standard | Based on Lean Body Mass |
| Accuracy | Highest for most adults | Overestimates slightly | Best if Body Fat % is known |
| Best For | Daily Calorie Tracking | Historical Comparison | Athletes / Bodybuilders |
| Goal | Balanced Weight Loss | Safety margin for gain | High-Precision Macro Math |
| Standard | Academy of Nutrition | Historical Medical Lit | Sports Science |
By using the BMR Calculator, you ensure your Dietary Foundation is built on sound physiological science.
Security and Privacy Considerations
Analyzing your metabolic health is a private, client-side process:
- Browser-Native Physiology: All math is performed locally in your browser. Your sensitive age, weight, and gender data are never sent to our servers.
- Zero Health Tracking: We do not store or log your metabolic profiles. Your Health Data and Bio-metrics remains entirely confidential.
- Sanitized Logic: The tool strictly validates inputs to ensure age and weight are positive values, preventing Logic Errors that could skew health advice.
- Privacy First: To maintain absolute Data Privacy, the tool functions as an anonymous utility without persistent tracking.