Calorie Calculator
Daily calorie needs (Mifflin-St Jeor)
This free Calorie Calculator estimates how many calories your body needs each day, using the Mifflin-St Jeor equation, which research generally finds to be the most accurate of the common formulas. It first works out your BMR — the energy you would burn in a full day of complete rest — from your sex, age, weight and height, then multiplies it by your activity level to give your TDEE, the calories that maintain your current weight. A simple goal table then shows sensible daily targets for losing, maintaining or gaining weight at steady, realistic rates.
Please treat every figure here as an estimate only, not medical advice. Real calorie needs vary with muscle mass, health conditions, medication, pregnancy and other factors that no short formula can capture, and individual results often differ by a few hundred calories a day. Very low calorie diets can be harmful, and the loss targets shown assume healthy adults; anyone who is pregnant, breastfeeding, under eighteen, or managing a medical condition should talk to a doctor or registered dietitian before changing how they eat. Everything runs locally in your browser, so your personal details are never uploaded or stored.
How to use
- Select your sex and enter your age in years.
- Enter your current weight in kilograms and height in centimetres.
- Choose the activity level that honestly matches a typical week.
- Click Calculate calories to see your BMR, TDEE and goal table.
- Use the maintenance figure as your starting point and adjust from real results.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is the energy your body uses just to stay alive at rest — breathing, circulation, cell repair. TDEE is BMR plus everything you actually do: walking, working, exercising and even digesting food. Weight stays stable when you eat around your TDEE.
How accurate is the Mifflin-St Jeor formula?
Studies comparing formulas against measured energy use usually rank it best for the general population, but it is still an estimate. Treat the number as a starting point, track your weight for two or three weeks, and nudge intake up or down based on what really happens.
Why does the goal table use 500 calories?
One kilogram of body fat stores roughly 7,700 calories, so eating about 500 fewer calories per day than you burn adds up to roughly half a kilogram lost per week. That pace is widely considered steady and sustainable for most healthy adults.
Which activity level should I choose?
Be honest rather than hopeful: pick the level matching your average week, not your best one. Most desk workers who train a few times a week land on Light or Moderate. Overestimating activity is the most common reason calorie targets disappoint.