Find your daily calorie needs based on age, sex, height, weight, and activity level - plus targets for losing or gaining weight.
This estimates the calories needed to maintain your current weight (TDEE). Individual needs vary - use this as a starting point, not a medical prescription.
This calculator estimates your Basal Metabolic Rate (BMR) - the calories your body burns at complete rest - using the Mifflin-St Jeor equation, the formula most widely used by dietitians today. For men, BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5. For women, BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161.
BMR alone isn't what you burn in a real day, since it doesn't include movement. Multiplying it by an activity factor gives your Total Daily Energy Expenditure (TDEE) - the number in the "Maintain" row, and the calorie total that keeps your weight steady over time.
Be honest rather than aspirational here, since overestimating activity is the most common reason these calculators feel "wrong" in practice. Sedentary means a desk job with little deliberate exercise. Light is a few short workouts a week. Moderate assumes 3-5 sessions of real exercise. Active and Very Active are for people training hard most days or working a physically demanding job - most people overestimate which bucket they're in.
A pound of body fat is roughly 3,500 calories. Eating about 500 calories below your TDEE most days creates a deficit that works out to around one pound lost per week; eating 500 above does the same in reverse for gaining. Smaller, slower changes (250 calories, about half a pound a week) are easier to sustain and are what most guidelines recommend over aggressive cuts.
Take a 30-year-old man, 5'9", 160 lb, with a moderate activity level. His BMR comes out to about 1,676 calories. Multiplied by the moderate activity factor (1.55), his TDEE - the calories that maintain his current weight - is about 2,598 calories a day. To lose roughly a pound a week he'd eat around 2,098 calories; to gain roughly a pound a week, around 3,098.
What's the difference between BMR and TDEE?
BMR is the energy your body uses just to stay alive at rest - breathing, circulation, cell repair. TDEE adds in everything else: walking, exercise, even fidgeting. TDEE is the more useful number day to day, since it's what actually determines whether you gain, lose, or maintain weight.
How many calories should I eat to lose weight safely?
A deficit of 250-500 calories below your TDEE is a commonly recommended range, working out to roughly half a pound to a pound of loss per week. Going far below your BMR is generally discouraged, since it can be hard to sustain and may not provide enough energy for normal function.
Is this calculator accurate for everyone?
It's a solid estimate for most adults, but the Mifflin-St Jeor formula was built from average body compositions. It tends to be less precise for people with unusually high muscle mass or body fat percentages, where a body-composition-based formula would run more accurate.
Does this work during pregnancy or breastfeeding?
No - calorie needs during pregnancy and breastfeeding follow different guidelines that this calculator doesn't account for. Talk to a doctor or registered dietitian for guidance specific to that situation.
I have a lot of muscle - will this underestimate my needs?
Possibly. Muscle burns more calories at rest than fat does, so a very muscular person's real BMR may run higher than Mifflin-St Jeor predicts. Treat the result as a starting point and adjust based on how your actual weight trends over a few weeks.
How often should I recalculate?
Whenever your weight changes by more than a few pounds, or roughly every 4-6 weeks if you're actively trying to lose or gain. TDEE shifts as your body weight changes, so the number that was accurate at the start of a diet won't stay accurate indefinitely.
Why did my real-world results not match the number here?
Every formula is an estimate, and actual metabolism varies by more than these equations can capture. Use the number as a starting point, track your weight for two to three weeks eating at that level, then adjust up or down 100-200 calories based on what actually happens.