Calorie Calculator
Find your daily calorie needs (TDEE) and a macro breakdown based on your goal - lose weight, maintain, or build muscle.
Recommended macro split for your selected goal:
Understanding your calorie needs
Every day, your body burns energy just to keep essential functions running — breathing, circulating blood, repairing cells, and regulating temperature. This baseline energy requirement is called your Basal Metabolic Rate (BMR), and it typically accounts for 60-70% of the calories most people burn in a day, even if they never leave the couch. On top of that baseline, your body burns additional calories through digestion, daily movement, and any structured exercise you do. Add all of that together and you get your Total Daily Energy Expenditure, or TDEE — the actual number of calories you'd need to eat to maintain your current weight.
This calculator uses the Mifflin-St Jeor equation to estimate your BMR. It was developed in 1990 and has consistently outperformed older formulas like the Harris-Benedict equation in accuracy studies across diverse body types, which is why registered dietitians and sports nutritionists commonly default to it today. From there, we multiply by an activity multiplier that accounts for how much you move throughout the week, giving you a realistic TDEE rather than a generic average.
Why the macro breakdown matters
Hitting a calorie target alone doesn't guarantee good results — where those calories come from matters almost as much as how many there are. Protein is the macronutrient most directly tied to preserving and building muscle, which is why this calculator increases your protein target specifically when your goal is weight loss (to protect muscle during a calorie deficit) or muscle gain (to support recovery and growth). Carbohydrates fuel your workouts and daily energy, and dietary fat supports hormone production and nutrient absorption. Rather than guessing at ratios, this tool calculates specific gram targets for each, scaled to your actual body weight and goal.
Common mistakes people make when calculating this manually
The most frequent error is using a generic "2000 calorie" rule of thumb that ignores individual differences in age, sex, height, weight, and activity level — two people of the same weight can have meaningfully different calorie needs based on these factors alone. Another common mistake is underestimating how sedentary a "moderately active" lifestyle actually is; many people who exercise three times a week still spend the rest of their day mostly sitting, which affects the activity multiplier that should be applied.
Is this accurate for everyone?
It's a solid estimate for most healthy adults, but individual metabolism varies due to factors like genetics, muscle mass, and hormonal differences. Use it as a starting point and adjust based on how your weight actually changes over 2-3 weeks of consistent tracking.
How much of a calorie deficit or surplus does this use?
Weight loss uses roughly a 20% deficit from maintenance, and muscle gain uses roughly a 10-15% surplus — both considered sustainable, moderate ranges rather than extreme changes. Aggressive deficits beyond this often lead to muscle loss and are harder to sustain long-term.
Should I recalculate over time?
Yes. As you lose or gain weight, your BMR shifts along with it, so recalculating every few weeks or after a meaningful weight change (roughly 5-10 lbs) keeps your targets accurate rather than working off outdated numbers.
Why does activity level matter so much?
Activity level is often the single biggest source of error in calorie calculations. Someone who sits at a desk all day and does no structured exercise burns significantly fewer calories than someone with the same body stats who's on their feet all day or trains hard five times a week — sometimes a difference of 500+ calories daily.
What if I'm not losing or gaining weight as expected?
Give any calorie target at least 2-3 weeks before adjusting — daily weight fluctuates due to water retention, sodium intake, and hormonal cycles, so short-term stalls are normal. If your weight genuinely isn't trending in the expected direction after that window, adjust your calorie target by roughly 100-200 calories and reassess.
This calculator provides general estimates for informational purposes only and is not a substitute for personalized advice from a doctor, dietitian, or other qualified health professional. Consult a professional before making significant changes to your diet, especially if you have any medical conditions.