BMR & Calorie Calculator
Estimate your Basal Metabolic Rate (BMR) and daily calorie needs based on your activity level using the Mifflin-St Jeor formula.
This is a general population-average estimate, not personalised medical or nutrition advice. See our Disclaimer.
The formula (Mifflin-St Jeor)
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5.
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161.
Total Daily Energy Expenditure (TDEE) is then BMR × an activity multiplier, giving a rough estimate of calories needed to maintain your current weight.
Worked example
A 30-year-old man weighing 70 kg at 175 cm has a BMR of 10×70 + 6.25×175 − 5×30 + 5 = 1,648.75 calories/day. With moderate activity (×1.55), his estimated maintenance calories are about 2,556/day.
Method and sources
The equation is Mifflin–St Jeor (Mifflin et al., American Journal of Clinical Nutrition, 1990), which was fitted to measured resting energy expenditure in healthy adults. The activity multipliers (1.2 to 1.9) are the conventional TDEE factors — rough averages, not measurements of you — so treat the result as a starting estimate. The worked example was recalculated independently in September 2026.
Frequently asked questions
What is BMR?
Basal Metabolic Rate is the number of calories your body needs at complete rest just to maintain basic functions like breathing and circulation — before any activity is added.
Should I eat exactly my TDEE?
TDEE is an estimate of maintenance calories. To lose weight, people typically eat somewhat below TDEE; to gain, somewhat above. Any significant change to your diet is worth discussing with a healthcare professional.