BMR & Daily Calorie Calculator
About this calculator
Your basal metabolic rate is the number of calories your body uses just to stay alive: breathing, circulation, temperature control and cell repair. This calculator estimates it with the Mifflin-St Jeor equation, then multiplies by an activity factor to give your daily maintenance calories.
Below the result you get calorie targets for five goals, from an extreme-loss day to a bulk, with the expected weekly change in weight. Choose centimetres or feet and inches, kilograms or pounds, and the tool converts for you.
How to use it
- Choose Male or Female.
- Enter your Age, Height and Weight in the units you prefer.
- Pick your Activity Level.
- Read your BMR, your maintenance calories and the calorie goals table.
The Mifflin-St Jeor equation
The Mifflin-St Jeor equation estimates basal metabolic rate (BMR), the energy your body burns at rest: Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 and Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161. Daily energy needs (TDEE) are BMR × activity factor, where the factor is 1.2 for a desk job, 1.375 for light exercise, 1.55 for moderate exercise, 1.725 for hard exercise and 1.9 for a very physical job plus training.
Worked example
Man, age 30, 170 cm, 70 kg, moderately active
| BMR | 1,618 kcal a day |
| Maintenance (BMR × 1.55) | 2,507 kcal a day |
| Weight loss (−0.45 kg a week) | 2,007 kcal |
| Lean bulk (+0.25 kg a week) | 2,757 kcal |
The same person as a woman would have a BMR of 1,452 and maintenance of about 2,250. These are estimates. Track your weight for two to three weeks to see if the number is right for you.
This tool gives general information, not medical advice. Talk to a doctor or dietitian before making changes to your diet, exercise or medication.
Tips and common mistakes
- Treat the result as a starting point. Adjust by 100 to 150 calories after two weeks of tracking your weight.
- Do not eat below your BMR for long without medical supervision.
- Muscle burns more than fat, so strength training raises your BMR over time.
- Be honest about activity. Most people overestimate it, and a lower factor is safer.
- Your needs change as you lose weight. Recalculate every 5 kg.
Frequently asked questions
What is BMR?
The energy your body needs at complete rest to keep vital functions going.
What is the difference between BMR and TDEE?
BMR is resting energy. TDEE adds the calories you burn moving, exercising and digesting food.
Which BMR formula is the most accurate?
Mifflin-St Jeor is widely regarded as the most accurate of the common equations for healthy adults.
How many calories should I cut to lose weight?
A deficit of about 500 calories a day leads to about 0.5 kg of loss a week. Larger cuts are harder to sustain.
Does BMR change with age?
Yes, it falls slowly with age, mainly as muscle mass declines.
Is the result exact?
No. It can be off by 10% or more, which is why tracking real results matters.