BMR Calculator - Basal Metabolic Rate (Mifflin-St Jeor)
Free online BMR calculator. Calculate your Basal Metabolic Rate (calories burned at rest) using validated Mifflin-St Jeor and Harris-Benedict formulas.
Inputs
🔒 Local Processing| Activity Level | Multiplier | Maintenance Calories |
|---|---|---|
| Sedentary (desk job) | 1.20 | 2051 kcal |
| Lightly Active (1-3 days/wk) | 1.375 | 2350 kcal |
| Moderately Active (3-5 days/wk) | 1.55 | 2649 kcal |
| Very Active (6-7 days/wk) | 1.725 | 2948 kcal |
How to Use This Calculator
- Enter gender, age, weight, and height to determine your minimum resting caloric expenditure.
Formula & Mathematical Method
Calculates the baseline calories required by the human body to sustain vital organs at complete rest.
BMR = 10×W(kg) + 6.25×H(cm) - 5×Age + (Male: +5, Female: -161)Explanation of Variables
| Symbol | Variable Name | Description & Role in Calculation |
|---|---|---|
| W | Body Weight | Body mass in kilograms. |
| H | Height | Stature in centimeters. |
| Age | Age in Years | Chronological age. |
Worked Calculation Examples
28-year-old male 75kg 175cm
Scenario: Resting BMR.
Interpretation of Results
Health and metabolic metrics are calculated using validated empirical equations (such as Mifflin-St Jeor, Devine, or Boer formulations). Results provide statistical estimates of physiological parameters for general wellness planning.
Estimated Physiological Value
Your calculated metabolic or anthropometric metric based on standard demographic averages.
Key Context: Use this figure as an informational baseline for nutritional or fitness goal setting.
Practical Use Cases
Nutritional and Fitness Program Design
Establish structured dietary intake targets, hydration goals, or training heart rate zones.
Long-Term Wellness Progress Tracking
Monitor changes in body composition, cardiovascular recovery, or metabolic requirements over time.
Limitations & Key Assumptions
- Formulas are derived from population-level clinical studies and cannot account for unique genetic, endocrine, or pharmacological differences.
- Hydration, body fat, and calorie needs fluctuate with daily temperature, humidity, stress, and hormonal cycles.
- Calculations are informational estimates and are NOT medical diagnoses, clinical evaluations, or therapeutic advice. Consult a qualified healthcare professional.