Calorie & BMR Calculator
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to keep you alive: breathing, circulation, cell repair. Your total daily calorie needs (TDEE) add the energy you burn through movement and exercise on top of that. This calculator estimates both using the Mifflin-St Jeor equation, the formula most widely recommended by nutrition professionals.
- BMR (calories at rest)
- 1,320 kcal/day
- Daily calories to maintain (TDEE)
- 2,046 kcal/day
- Mild weight loss (−500 kcal)
- 1,546 kcal/day
- Mild weight gain (+500 kcal)
- 2,546 kcal/day
Knowing your TDEE gives you a starting point for any goal: eat roughly at that level to maintain weight, moderately below it to lose weight, or above it to gain. A commonly cited guideline is a deficit or surplus of about 500 calories per day for a gradual change of roughly 1 lb (0.45 kg) per week.
How it's calculated
BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + s
In the Mifflin-St Jeor equation, s is +5 for men and −161 for women. Daily calories (TDEE) are then BMR multiplied by an activity factor: 1.2 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, 1.9 extremely active.
Worked example
A 30-year-old woman, 165 cm and 60 kg: BMR = 10×60 + 6.25×165 − 5×30 − 161 = 1,320 calories. If she is moderately active (exercise 3–5 days/week), her daily needs are about 1,320 × 1.55 ≈ 2,046 calories.
Frequently asked questions
›What is the difference between BMR and TDEE?
BMR is calories burned at complete rest. TDEE (Total Daily Energy Expenditure) is BMR plus everything else: walking, working, exercise, even digesting food. TDEE is the number to use when planning your diet.
›How accurate are these formulas?
Mifflin-St Jeor is accurate to within about 10% for most people, but individual metabolism varies. Track your weight for a few weeks at a given intake and adjust based on real results.
›Which activity level should I pick?
Be honest and conservative, because most people overestimate. Choose sedentary if you have a desk job and little exercise, lightly active for 1 to 3 workouts a week, and moderately active for 3 to 5.
›Is a bigger calorie deficit better for weight loss?
Not usually. Very large deficits are hard to sustain, cost muscle mass, and can slow metabolism. Most guidance suggests losing no more than about 1% of body weight per week.
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