Short answerFor body recomposition, eat about maintenance on training days and 20% less on rest days, get around 2 g of protein per kilogram of body weight, and lift 3 to 5 times a week. A 150-pound woman with 30% body fat who trains 3 days a week would eat about 1,920 calories on training days and 1,540 on rest days, with 136 g of protein.
What is body recomposition?
Body recomposition, or body recomp, means changing what your body is made of: less fat, more muscle. Instead of a classic diet, where you lose weight and some muscle with it, you aim to swap one for the other. The scale may not move much, but your waist gets smaller, your clothes fit differently and you get stronger. For what to eat while you do it, see our diet for good abs.
A review of the research found recomposition happens most reliably in four groups: people new to strength training, people coming back after a break, people with more body fat to lose, and, more slowly, trained lifters who get their protein and training right. The calculator's "recomp outlook" reflects this. If your goal is mostly to lose weight rather than change shape, the weight loss simulator is the better planning tool.
How the body recomposition calculator works
Like any good body recomp calorie calculator, it starts from what you're made of, not just what you weigh:
- Lean mass. Weight × (1 − body fat %). Everything that isn't fat: muscle, bone, organs and water.
- Maintenance. The Katch-McArdle equation, 370 + 21.6 × lean mass in kg, gives your resting burn (the BMR calculator compares it with two other equations). It's multiplied by an activity factor based on your training days.
- Calorie cycling. Training days stay at maintenance so you can lift well. Rest days drop 20%. Across the week that's a small deficit without long, hungry stretches.
Here's a worked example: a 30-year-old man, 5'11" and 187 pounds (85 kg), with 22% body fat, lifting 4 days a week. His lean mass is 66.3 kg, so Katch-McArdle gives a BMR of about 1,800. Maintenance at 4 training days is about 2,790 calories. His rest days are about 2,235, and the weekly average comes to about 2,550: some 1,680 calories under maintenance across the week.
This body recomposition calorie calculator keeps the deficit small on purpose. A big deficit costs muscle; recomposition is about protecting and building it while fat comes off slowly.
Macros for body recomp
Protein is the anchor of this body recomp macro calculator. Studies on muscle growth point to about 1.6 g of protein per kilogram of body weight a day, with benefits for some people up to 2.2 g/kg. The calculator uses 2.0 g/kg, which also helps keep muscle while you're eating less on rest days. Fat is set at 25% of calories, and carbs fill the rest, so carbs rise on training days, when they help you train hard.
| Person | Training day | Rest day |
|---|---|---|
| Woman, 5'5", 150 lb, 30% fat, 3 days a week | 1,922 kcal: 136 g protein, 224 g carbs, 53 g fat | 1,538 kcal: 136 g protein, 152 g carbs, 43 g fat |
| Man, 5'11", 187 lb, 22% fat, 4 days a week | 2,793 kcal: 170 g protein, 354 g carbs, 78 g fat | 2,235 kcal: 170 g protein, 249 g carbs, 62 g fat |
Want a full macro calculator for body recomposition with other eating styles, like low carb or keto? Use our macro calculator with the "Lose fat, keep muscle" goal.
Don't know your body fat? Use a tape measure
The calculator can estimate body fat with the U.S. Navy method, which uses your height and a few circumference measurements:
- Men: neck and waist (at the navel)
- Women: neck, waist (narrowest point) and hips (widest point)
It's usually within a few percentage points of lab methods, which is close enough to set targets. Measure in the morning, relaxed, with the tape snug but not tight. Use the same method each time you recheck, because the trend matters more than the exact number.
Goal weight from body fat
If you keep your lean mass, your weight at a goal body fat is lean mass ÷ (1 − goal %). The 150-pound woman above has 47.6 kg (105 lb) of lean mass. At 25% body fat, she'd weigh about 63.5 kg, or 140 pounds, after losing about 10 pounds of fat. Add a few pounds of muscle along the way and she'd land around 142 to 145, with a smaller waist than a pure diet would give.
Body recomposition for women
The body recomposition calculator for women works the same way, with two differences. First, healthy body fat ranges sit higher for women, so a goal of 22 to 28% is common where men might aim for 12 to 18%. Second, women's weight can swing a few pounds with the menstrual cycle, which makes the scale even less useful during a recomp. Compare measurements and photos at the same point in your cycle each month.
How long does a recomp take?
Most people see a difference in the mirror and in their clothes after 8 to 12 weeks of steady training, and a clearer change after 6 months. Beginners progress fastest. Track these every 2 to 4 weeks:
- Waist and hip measurements
- Photos in the same light and pose
- Strength: are your lifts going up?
- Body weight as a weekly average, not daily
- What you eat, in the calorie counter, so training and rest days land on target
If your weight drops fast and your lifts stall, you're eating too little. If nothing changes for 6 weeks, take 100 to 150 calories off the rest days. It's also motivating to check your metabolic age at the start and every couple of months; it moves as muscle replaces fat.
Body recomp FAQ
What is body recomposition?
Body recomposition means losing fat and gaining muscle at the same time, so your shape changes more than your weight. It works best for beginners, people returning to training and people with more body fat to lose.
How many calories should I eat for body recomp?
Eat around maintenance on training days and about 20% less on rest days. That gives a small weekly deficit while still fueling your workouts.
What macros should I use for body recomposition?
High protein, about 1.6 to 2.2 grams per kilogram of body weight a day, fat around 25% of calories, and the rest from carbs, with more carbs on training days.
How long does body recomposition take?
Expect visible changes in about 8 to 12 weeks of consistent training and eating. The scale may barely move, so track measurements, photos and strength too.
Sources
- Barakat C, Pearson J, Escalante G, Campbell B, De Souza EO. Body recomposition: can trained individuals build muscle and lose fat at the same time? Strength Cond J, 2020;42(5):7–21.
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength. Br J Sports Med, 2018.
- Hodgdon JA, Beckett MB. Prediction of percent body fat for U.S. Navy men and women from body circumferences and height. Naval Health Research Center, reports 84-11 and 84-29, 1984.
- McArdle WD, Katch FI, Katch VL. Exercise Physiology: Nutrition, Energy, and Human Performance (Katch-McArdle equation).