Get your daily calorie, protein, carb, fat, and fiber targets for fat loss, built to protect lean muscle if you're on a GLP-1 like semaglutide or tirzepatide.
All fields are needed for an accurate result.
Your calorie target starts with the Mifflin-St Jeor equation, the resting-metabolic-rate formula recommended by the Academy of Nutrition and Dietetics for its accuracy across body types. That number is scaled by your activity level to estimate maintenance calories (TDEE), then a deficit is subtracted based on your chosen fat loss pace. From there, each macro is set with a specific job to do:
Set before anything else since it's most responsible for preserving muscle: ~0.8g per lb of body weight, or 1g per lb on a GLP-1.
Held at roughly 25% of total calories, enough to support hormone production without crowding out protein or carbs.
Whatever calories remain go to carbs, fueling workouts and recovery so the deficit doesn't tank performance.
Follows the USDA guideline of about 14g per 1,000 calories, which keeps digestion and satiety in check on fewer calories.
Answers to what people ask most before trusting a number this important.
The calculator uses the Mifflin-St Jeor equation to estimate your resting metabolic rate from your weight, height, age, and sex, multiplies it by an activity factor, then subtracts a deficit based on your chosen fat loss pace.
A moderate deficit (~350 cal/day, 0.5-0.75 lb/week) is easier to sustain and better preserves muscle. An aggressive deficit (~650 cal/day, 1-1.5 lb/week) works faster but is harder to stick with. A 1,200 (women) / 1,500 (men) calorie floor is built in for safety.
GLP-1 medications suppress appetite, making it easy to under-eat protein without noticing. Low protein during a deficit raises the risk of losing muscle along with fat, so the target is raised to about 1g per pound of body weight for GLP-1 users.
No. Your activity level selection already accounts for your typical exercise, so your daily target reflects an average day. Eating back workout calories on top would cancel out part of the deficit already built in.
Recalculate every 10 to 15 pounds lost, or roughly every 4 to 6 weeks, since both maintenance calories and the deficit needed to keep progressing shift as body weight drops.
It gives a solid, evidence-based starting point, but no calculator accounts for individual medical conditions, medications, or body composition. Treat it as a starting point and check with a healthcare provider before an aggressive deficit or a new medication.
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