BMR and Daily Calorie Calculator
Enter your age, sex, height, and weight to estimate your basal metabolic rate (BMR), the energy your body burns at rest, and your total daily energy expenditure (TDEE) once your activity level is factored in. Choose between the Mifflin-St Jeor equation (the default), the revised Harris-Benedict equation, or the reference values used in Japanese dietary guidelines, and see rough calorie targets for losing or gaining weight. Everything is calculated in your browser, and nothing you type is sent to a server. To check your weight category, try the BMI Calculator as well.
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Notes
- Results are statistical estimates. Actual metabolism varies with muscle mass, genetics, and health, and this is not medical or nutrition advice.
- The activity multipliers (1.2 to 1.9) are the ones commonly used with the Harris-Benedict equation, and they differ from the physical activity levels (1.50, 1.75, 2.00) in Japanese dietary guidelines.
- The weight loss and gain targets are simple percentages of maintenance calories. Avoid extreme restriction, especially if a target falls below your BMR.
- The Japanese reference values are available for age 18 and over only. If you are pregnant, breastfeeding, or have a medical condition, talk to a doctor or dietitian.
Glossary
BMR (Basal Metabolic Rate)
The energy your body uses at complete rest for breathing, keeping warm, and running your organs. It makes up roughly 60–70% of daily calorie burn and varies with age, sex, and body size, tending to be higher with more muscle.
TDEE (Total Daily Energy Expenditure)
The total energy you burn in a day, found by multiplying BMR by an activity factor. Eating about this many calories keeps weight roughly stable; eating less tends to lose weight and eating more tends to gain it.
Mifflin-St Jeor vs Harris-Benedict
Both estimate BMR from height, weight, age, and sex. Mifflin-St Jeor (1990) was built on more modern data and is generally considered more accurate. Harris-Benedict dates from 1919 and had its coefficients revised in 1984.
FAQ
What is the difference between BMR and daily calories burned?
BMR is the energy you burn just by staying at rest. Your daily calorie needs (TDEE) add the energy from work and exercise, and are found by multiplying BMR by an activity factor from 1.2 to 1.9.
Which equation should I choose?
If unsure, use Mifflin-St Jeor (the default). The revised Harris-Benedict equation tends to give slightly higher numbers. The Japanese option multiplies your weight by an age-group value from Japan’s dietary reference intakes and applies to adults 18 and over.
How many calories should I cut to lose weight?
A common range for gradual weight loss is 10–20% below your maintenance calories. Eating far below your BMR can cost muscle and harm your health, so avoid extreme cuts and talk to a doctor or dietitian if you are unsure.
Why does the result not match how my body behaves?
Every equation estimates an average from age, sex, height, and weight only, so muscle mass, body fat, and genetics are not reflected. Treat the result as a starting point and adjust based on how your weight changes.
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