Calorie Calculator — Daily Calorie Needs (BMR & TDEE)
A calorie calculator estimates how many calories you need each day, using the Mifflin-St Jeor equation for your basal metabolic rate (BMR) and your activity level for total daily energy (TDEE).
How it works
- Enter your sex, age, weight and height.
- Choose your activity level, from sedentary to very active.
- See your BMR, your maintenance calories, and targets for losing or gaining weight.
Formula
Worked example
A 33-year-old man weighing 76 kg and 179 cm tall has a BMR of about 1,719 calories a day (10×76 + 6.25×179 − 5×33 + 5). With moderate activity (factor 1.55), his maintenance intake is about 2,664 calories a day. To lose weight slowly, he would aim for about 2,164 calories a day.
Frequently asked questions
How many calories should I eat a day?
It depends on your size, age, sex and activity. A moderately active 33-year-old man (76 kg, 179 cm) needs about 2,664 calories a day to maintain weight. Enter your details above for your number.
How do I calculate a calorie deficit for weight loss?
Eat about 300–500 calories below your maintenance (TDEE) for slow, steady loss of about 0.5 kg a week. Larger deficits are harder to sustain — check with a health professional first.
What is BMR vs TDEE?
BMR is the energy your body uses at complete rest. TDEE is BMR multiplied by an activity factor, and is your total daily burn including movement and exercise.
What is the Mifflin-St Jeor equation?
It is the most widely used formula for estimating BMR from weight, height, age and sex. It was published in 1990 and is still the standard in nutrition practice.
How many calories do I need to maintain weight?
Eat at your TDEE — the maintenance figure shown by the calculator. If your weight stays stable over a few weeks, you have found your maintenance level.
Are calorie calculators accurate?
They give a good estimate, usually within about 10%. Real needs vary with muscle mass, health and daily movement, so treat the result as a starting point and adjust by what the scales show.