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Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation - the most accurate BMR formula for modern populations, recommended by nutrition professionals worldwide.
The Mifflin-St Jeor equation is considered the gold standard for calculating BMR in modern populations. Published in 1990, it's more accurate than the older Harris-Benedict equation and is recommended by the Academy of Nutrition and Dietetics.
The Mifflin-St Jeor equation was developed by MD Mifflin, ST St Jeor, and colleagues in 1990 after studying 498 healthy adults. Their research showed it predicted resting energy expenditure within 10% for 82% of participants - better than any previous equation.
Healthcare providers and registered dietitians prefer Mifflin-St Jeor for meal planning, weight management programs, and clinical nutrition interventions. It's the default equation in most professional nutrition software.
While Mifflin-St Jeor is excellent for most people, other equations may be better for:
| Factor | Mifflin-St Jeor (1990) | Harris-Benedict (1984) |
|---|---|---|
| Publication Year | 1990 | 1984 (revised from 1918) |
| Sample Size | 498 healthy adults | 239 subjects (original 1918) |
| Accuracy (within 10%) | 82% of population | ~75% of population |
| For Obese Individuals | More accurate | May overestimate |
| Professional Recommendation | Preferred by AND | Still widely used |
| Formula Complexity | Simpler (round numbers) | More complex coefficients |
| Modern Population | Better fit | Slightly outdated |
| Typical Difference | Usually 5-10% lower than Harris-Benedict | |
Bottom line: Both equations are valid and give similar results. Mifflin-St Jeor is slightly more accurate for modern populations and is the preferred choice of nutrition professionals. The difference between them is typically only 50-150 calories per day.
The Mifflin-St Jeor equation is a formula to calculate Basal Metabolic Rate (BMR) based on weight, height, age, and biological sex. Published in 1990, it's considered more accurate than the older Harris-Benedict equation for modern populations.
Mifflin-St Jeor was developed using data from late 20th century subjects, better reflecting modern body compositions and lifestyles. Studies show it predicts BMR within 10% for 82% of people, compared to ~75% for Harris-Benedict.
It's reasonably accurate but may underestimate BMR for very muscular individuals. Athletes with high muscle mass should consider the Katch-McArdle equation, which accounts for lean body mass.
Yes. Calculate your TDEE using Mifflin-St Jeor, then create a 10-25% calorie deficit (300-500 calories below TDEE) for sustainable weight loss. Track for 2-4 weeks and adjust as needed.
BMR (Basal Metabolic Rate) is calories burned at complete rest. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor to account for all daily activities and exercise.
Recalculate every 10-15 pounds of weight change, or every 3-6 months. BMR decreases as you lose weight and age, so periodic updates ensure accuracy.
Short-term is okay, but consistently eating below BMR can slow metabolism, cause muscle loss, and create hormonal issues. A safer approach is 10-25% below TDEE, not BMR.
Men typically have more muscle mass and less body fat percentage than women of the same weight, leading to higher metabolic rates. The +5 for men and -161 for women accounts for these biological differences.
This calculator provides estimates for educational purposes only. The Mifflin-St Jeor equation is highly accurate for most people but may not account for individual variations in genetics, body composition, medical conditions, or medications affecting metabolism. Consult with a registered dietitian or healthcare provider for personalized nutrition guidance, especially if you have medical conditions or are taking medications.