Mifflin-St Jeor Calculator — Calculate Your BMR & Daily Calories Free
Use the most accurate calorie calculator trusted by nutritionists. Enter your age, weight, height, and activity level to get your personalized BMR and TDEE instantly.
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BMR
1680
calories/day
TDEE
2604
calories/day
Fat Loss
2104
calories/day
-500 cal/day
Weight Gain
3104
calories/day
+500 cal/day
Maintenance: 2604 calories/day
These are estimates. Individual needs vary. Consult a healthcare professional for personalized advice.
What Your Results Mean
What Is BMR (Basal Metabolic Rate)?
Your basal metabolic rate (BMR) is the foundational baseline of your metabolism. It represents the exact number of daily calories your body requires just to stay alive if you were to stay in bed all day.
Even when you are completely at rest, your body is working hard behind the scenes — pumping blood, breathing, regulating body temperature, and repairing cells.
Think of your BMR as your body's "engine idling" cost.
What Is TDEE (Total Daily Energy Expenditure)?
While your BMR covers your survival energy, your total daily energy expenditure (TDEE) accounts for everything else you do. Your TDEE is the total amount of daily calorie needs based on your active lifestyle.
It is calculated by multiplying your baseline BMR by an activity level multiplier.
The Mifflin-St Jeor equation uses five distinct activity tiers to find your TDEE:
- 1Sedentary (BMR × 1.2): Little to no exercise; desk job lifestyle.
- 2Lightly Active (BMR × 1.375): Light exercise or sports 1 to 3 days per week.
- 3Moderately Active (BMR × 1.55): Moderate exercise or sports 3 to 5 days per week.
- 4Very Active (BMR × 1.725): Hard exercise or intense sports 6 to 7 days per week.
- 5Extra Active (BMR × 1.9): Very strenuous daily exercise, physical labor, or double training sessions.
Which Calorie Goal Is Right for You?
Once our BMR calculator reveals your TDEE, you can map out how many calories you should eat to hit your personal goals. Your target splits into three main paths:
Fat Loss
Calorie Deficit: To lose weight, consume 500 calories fewer than your TDEE. This forces your body to burn stored fat for fuel, resulting in healthy, sustainable weight loss.
Maintenance
Calorie Balance: Eating at your TDEE maintains your current weight. Perfect for those who have reached their goal and want to stay there.
Weight Gain
Calorie Surplus: To build muscle, add 300-500 calories above your TDEE. Combined with strength training, this supports muscle growth.
The Mifflin-St Jeor Equation
The Mifflin-St Jeor equation was developed in 1990 and is considered the most accurate formula for calculating BMR. It is widely used by nutritionists and healthcare professionals.
For Men:
BMR = (10 × weight) + (6.25 × height) - (5 × age) + 5
For Women:
BMR = (10 × weight) + (6.25 × height) - (5 × age) - 161
Note: Weight is in kilograms, height is in centimeters, and age is in years.
Frequently Asked Questions
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Use our free Mifflin-St Jeor calculator to discover your BMR and TDEE. Start your fitness journey with accurate calorie targets today.
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