Calorie Calculator — Daily Calorie Needs
Estimate your BMR and daily calorie needs (TDEE) based on your stats and activity level.
About the Calorie Calculator
This calculator estimates two numbers: your BMR (Basal Metabolic Rate) — the calories your body burns at complete rest just to keep organs functioning — and your TDEE (Total Daily Energy Expenditure), which adds in your activity level to estimate the calories you burn in a typical day. It uses the Mifflin-St Jeor equation, which is generally considered more accurate than older formulas like Harris-Benedict for most adults.
TDEE is a useful baseline for weight goals: eating around your TDEE tends to maintain weight, eating consistently below it tends to produce weight loss, and eating above it tends to produce weight gain. This calculator shows your maintenance calories along with common targets for mild weight loss and weight gain.
Worked example
Example: a 30-year-old man, 180 cm tall, weighing 80 kg, with a moderately active lifestyle has a BMR of roughly 1,780 calories and a TDEE of about 2,760 calories per day at maintenance.
Frequently asked questions
- What is BMR and how is it different from TDEE?
- BMR is the calories your body needs at complete rest, with no activity at all. TDEE takes BMR and multiplies it by an activity factor to estimate total calories burned in a full day including exercise, walking, and daily movement — it's always higher than BMR.
- How accurate is the Mifflin-St Jeor equation?
- It's one of the most accurate predictive equations validated in research for the general population, but any formula is an estimate — actual metabolism varies by individual factors like muscle mass, genetics, and health conditions. Use it as a starting point and adjust based on real-world results over a few weeks.
- How many calories should I eat to lose weight?
- A commonly cited approach is a deficit of about 500 calories per day below TDEE for roughly 0.5 kg (about 1 lb) of weight loss per week, though this calculator's estimate should be adjusted for your own results — and significant or rapid weight loss should involve a doctor or registered dietitian.
- Why does activity level change the result so much?
- Activity level is multiplied against BMR, so small differences in the multiplier compound across a whole day. Someone who's sedentary versus very active can have a TDEE difference of 800–1000+ calories even with identical BMR, since movement and exercise burn calories on top of baseline metabolism.