Calorie Calculator: BMR and TDEE
What is Calorie Calculator: BMR and TDEE
A calorie calculator estimates how many calories your body burns each day. It first works out your Basal Metabolic Rate (BMR), the energy you burn at complete rest, using the Mifflin-St Jeor equation from your sex, age, height, and weight. It then multiplies that by an activity factor to estimate your Total Daily Energy Expenditure (TDEE), the calories you burn including movement and exercise. TDEE is your maintenance number: eat around that amount and your weight stays roughly stable.
How to use
- Select your sex (male or female).
- Enter your age in years.
- Choose Metric (cm/kg) or Imperial (ft+in/lbs) and enter your height and weight.
- Pick the activity level that best matches your weekly exercise routine.
- Read your BMR, TDEE, and suggested calorie targets instantly.
When to use it
Trying to figure out how much to eat before starting a diet or a bulk? Enter 180 cm, 80 kg, age 30, moderately active, and you get a BMR around 1780 kcal/day and a TDEE around 2759 kcal/day, with a 2259 kcal/day target to lose roughly 0.5 kg a week. That gives you a concrete calorie number to build a meal plan around instead of guessing.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is the number of calories your body burns at complete rest, just to keep your organs and basic functions running. TDEE adds your daily activity on top of that, including exercise, walking, and general movement, so it is always higher than BMR.
How is BMR calculated?
This calculator uses the Mifflin-St Jeor equation: for men, BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5. For women, subtract 161 instead of adding 5. It is considered one of the most accurate formulas for the general population.
How many calories should I eat to lose weight?
A deficit of about 500 kcal/day below your TDEE leads to roughly 0.5 kg of weight loss per week, a widely recommended, sustainable pace. A milder 250 kcal/day deficit gives about 0.25 kg a week with less impact on energy levels.
Is this calculator accurate for athletes or bodybuilders?
The Mifflin-St Jeor equation is validated for the general population but can underestimate BMR in very muscular people, since muscle burns more calories than fat. Treat the result as a starting point and adjust based on how your weight actually changes over a few weeks.
Can I share this tool with my inputs pre-filled?
Yes. The URL updates automatically as you type. Copy it from the address bar or use the Share button, anyone who opens the link will see your exact inputs ready to go.
Related tools
A-a Gradient Calculator
Calculate the alveolar-arterial oxygen gradient from FiO2, PaO2 and PaCO2, and compare it to the expected value for age. Free and instant.
How Old Am I? Age Calculator
Find out exactly how old you are with this free age calculator. Enter your date of birth and get your age in years, months, days, zodiac sign, and more.
Anion Gap Calculator
Calculate the serum anion gap from sodium, chloride and bicarbonate, with optional potassium and albumin correction, to screen for metabolic acidosis.