If you’re trying to lose weight, build muscle, or simply maintain your current weight, understanding your Basal Metabolic Rate (BMR) and daily calorie needs is essential.
What Is BMR?
BMR stands for Basal Metabolic Rate — the number of calories your body burns at complete rest just to maintain basic functions like breathing, circulation, and cell production. It accounts for about 60-75% of your total daily energy expenditure.
What Is the Mifflin-St Jeor Equation?
The most accurate formula for estimating BMR is the Mifflin-St Jeor equation. Our BMR calculator uses this formula:
For men: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age(y) + 5
For women: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age(y) - 161
From BMR to Total Daily Energy Expenditure (TDEE)
Your BMR is just the starting point. To find your actual daily calorie needs, multiply your BMR by an activity factor:
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise | BMR x 1.2 |
| Lightly active | Exercise 1-3 days/week | BMR x 1.375 |
| Moderately active | Exercise 3-5 days/week | BMR x 1.55 |
| Very active | Exercise 6-7 days/week | BMR x 1.725 |
| Extra active | Physical job + daily exercise | BMR x 1.9 |
Our calorie calculator does this automatically and also provides a macro breakdown.
Setting Calorie Goals
Once you know your maintenance calories (TDEE), you can set goals:
- Weight loss: TDEE minus 300-500 calories per day (lose about 0.5 kg/1 lb per week)
- Weight gain (bulk): TDEE plus 300-500 calories per day
- Maintenance: Eat at your TDEE
Macro Breakdown
For balanced nutrition, split your calories into:
- Protein: 30% of calories (or 1.6-2.2 g per kg of body weight)
- Carbohydrates: 40-50% of calories
- Fat: 20-30% of calories
Our calorie calculator provides a full macro split based on your goals.
Common Mistakes
- Not recalculating after weight loss — Your BMR decreases as you lose weight; recalculate every 5-10 kg
- Overestimating activity level — Most people overestimate how active they are; be honest
- Not tracking consistently — Use a food scale and tracking app for accuracy
Summary
Your BMR is the foundation of weight management. Use our BMR calculator to find your baseline, then use the calorie calculator to set daily targets with a complete macro breakdown.