Find out exactly how many calories and macros your body needs - for weight loss, muscle gain, or maintenance.
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For informational purposes only
This calculator provides estimates based on established scientific formulas. Results are not medical or nutritional advice. Individual needs vary. Consult a registered dietitian or healthcare provider before making significant dietary changes, especially if you have a medical condition.
Science-based calorie and macro planning
A good calorie calculator should do more than estimate a number. It should explain how your maintenance calories are derived, help you choose an appropriate deficit or surplus, and translate the result into a macro plan you can actually follow. This page walks through the full workflow: calculate TDEE, review your calorie target for your goal, and translate that target into a macro split you can apply to everyday meals.
How to calculate calories for weight loss, maintenance, and muscle gain
Your maintenance calories start with BMR, or basal metabolic rate, which estimates how much energy your body uses at rest. This calculator then applies an activity multiplier to estimate TDEE, your total daily energy expenditure. From there, your goal determines the calorie target: a deficit for fat loss, maintenance for bodyweight stability, or a surplus for muscle gain. Using TDEE instead of guessing helps you set a target that is specific to your size, activity level, and body composition.
Why macros matter after you know your calorie target
Calories determine whether you lose, maintain, or gain weight, but macros influence how that change feels and what kind of tissue you preserve or build. A higher protein target can improve satiety and support lean mass retention during a cut. Carbohydrates help with training performance and recovery, while dietary fat supports hormones and long-term adherence. Once your TDEE is set, splitting calories into protein, carbs, and fat gives you a more practical macro plan than calories alone.
When to recalculate your TDEE and macro targets
TDEE is not fixed. As bodyweight, body fat, training volume, or daily movement changes, your true maintenance level changes too. A good rule is to recalculate every few weeks, or sooner if your average bodyweight shifts noticeably. If progress stalls, your calorie target may need an update rather than a more aggressive cut or reverse diet. Re-running the calculator keeps your plan aligned with the data instead of forcing old numbers to fit new conditions.
Frequently asked questions
What is TDEE?
TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns each day, including your basal metabolic rate (BMR) plus all physical activity. It represents your true maintenance calorie level - the number of calories needed to stay at your current weight.
How is TDEE calculated?
TDEE is calculated by multiplying your BMR by an activity multiplier. Your BMR is estimated using formulas (Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle) based on your height, weight, age, and sex. The result is multiplied by a factor from 1.2 (sedentary) to 2.0 (professional athlete) to account for daily movement.
What are macros and why do they matter?
Macros (macronutrients) are the three main nutrients: protein, carbohydrates, and fat. Protein and carbs each provide 4 calories per gram; fat provides 9. Tracking macros - not just calories - helps preserve muscle during a cut, supports muscle growth during a bulk, and ensures you're getting balanced nutrition.
Which formula is most accurate - Mifflin-St Jeor vs Harris-Benedict?
Mifflin-St Jeor (1990) is generally the most accurate for the average person, with a mean error of around 5%. Harris-Benedict (revised 1984) tends to overestimate for sedentary individuals. Katch-McArdle is the most accurate formula when you know your body fat percentage, because it accounts for lean body mass directly.
Should I use Imperial or metric units?
Both are equally accurate - this calculator converts all values internally before running calculations. Use whichever unit system you're most familiar with. Familiarity reduces measurement errors, which is more important than the unit system itself.
How often should I recalculate my TDEE?
Recalculate every 4-6 weeks, or whenever your weight changes by more than 5 lbs (2.3 kg). As your body composition shifts - whether losing fat or gaining muscle - your BMR changes too. Regular recalculation keeps your calorie targets accurate and helps you avoid plateaus.
What calorie deficit is safe for weight loss?
A deficit of 500 calories per day is widely considered safe, producing roughly 1 pound (0.45 kg) of weight loss per week. Deficits above 1,000 calories per day risk muscle loss and nutrient deficiencies. Very low-calorie diets (under 1,200 cal/day for women, 1,500 for men) should only be used under medical supervision.
What is a lean bulk vs a dirty bulk?
A lean bulk uses a modest calorie surplus of 250-500 calories per day to build muscle while minimizing fat gain - slower but cleaner results. A dirty bulk uses a large, uncontrolled surplus (often 1,000+ cal/day), gaining muscle faster but with significant fat accumulation that requires a longer cutting phase later.
