Body Recomposition Calculator
Calculate your calorie and macro targets for body recomposition — losing fat while building muscle at the same time. Get separate nutrition plans for training days and rest days based on the Mifflin-St Jeor equation. 100% private.
What Is Body Recomposition?
Body recomposition is the process of losing body fat and building lean muscle mass at the same time. Unlike traditional bulking and cutting cycles, recomposition uses calorie cycling — eating slightly more on training days and slightly less on rest days — to fuel muscle growth while maintaining an overall mild deficit for fat loss. Based on the Mifflin-St Jeor equation, this calculator provides personalized daily calorie and macronutrient targets for both training and rest days.
Mifflin-St Jeor BMR Equation
Male BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5
Female BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161
TDEE = BMR x Activity Multiplier
Training Day = TDEE + 5-10% surplus
Rest Day = TDEE - 10-15% deficit
How Body Recomposition Macros Work
Protein is the most critical macronutrient for recomposition. Research recommends 1.0 to 1.2 grams of protein per pound of body weight to maximize muscle protein synthesis while in a deficit. Dietary fat is set at 0.3 to 0.4 grams per pound to support hormone production, especially testosterone. The remaining calories come from carbohydrates, which are higher on training days to fuel workouts and recovery, and lower on rest days when energy demands are reduced.
Who Should Try Body Recomposition?
Body recomposition works best for beginners to intermediate lifters, people returning to training after a break, and those with moderate body fat (15-25% for men, 25-35% for women). Advanced athletes with low body fat may find traditional bulk/cut cycles more effective. If you have a body fat estimate, entering it improves the accuracy of your protein recommendation. The key to successful recomp is consistency — tracking your training day and rest day nutrition, lifting progressively heavier weights, and getting adequate sleep for recovery.
Tips for Successful Recomposition
Prioritize compound exercises like squats, deadlifts, bench press, and rows on training days. Aim for 3 to 6 resistance training sessions per week. Sleep 7 to 9 hours per night — growth hormone is released during deep sleep. Track your progress with body measurements and progress photos rather than the scale alone, since your weight may stay the same while your body composition improves dramatically. Weigh yourself at the same time each day and use weekly averages to track trends.
Frequently Asked Questions
What is body recomposition?
Body recomposition (recomp) is the process of simultaneously losing body fat and gaining muscle mass. Instead of separate bulking and cutting phases, you use calorie cycling — eating at a slight surplus on training days to fuel muscle growth and a slight deficit on rest days to promote fat loss.
How does calorie cycling work for recomp?
Calorie cycling means eating more on days you lift weights (typically 5-10% above TDEE) and less on rest days (10-15% below TDEE). This gives your muscles the fuel they need for growth and recovery while maintaining an overall mild weekly deficit for fat loss.
Why is protein so high for body recomposition?
Protein at 1.0-1.2g per pound of body weight is essential during recomp because you need enough amino acids to build new muscle tissue while in an overall caloric deficit. Research shows higher protein intakes preserve and build lean mass even during fat loss phases.
How long does body recomposition take to see results?
Most people notice visible changes in 8-12 weeks with consistent training and nutrition. Progress photos and body measurements are better indicators than the scale, since you may lose fat and gain muscle at similar rates, keeping your weight stable while your body composition improves.
Who gets the best results from body recomposition?
Beginners, people returning after a training break, and those with moderate body fat (15-25% for men, 25-35% for women) see the best recomp results. Advanced lifters with low body fat may benefit more from traditional bulk and cut cycles.
Is this calculator accurate?
This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate BMR estimation for healthy adults (within about 10%). Your actual results may vary based on genetics, sleep quality, stress, and training intensity. Use the numbers as a starting point and adjust based on weekly progress.
Is my health data private?
Yes. All calculations run entirely in your browser. No personal data is sent to any server or stored externally.