Cutting and bulking use nearly the same protein target, about 1.6 to 2.2 g per kilogram of body weight per day, and differ mainly in calories: roughly 10 to 25 percent below maintenance for a cut and 10 to 20 percent above it for a bulk. Fat keeps a similar share in both phases, and carbohydrates absorb most of the difference. In short, the phase you pick changes the calorie total and the carb number far more than it changes protein.
The fastest way to get real numbers is to estimate maintenance with the TDEE Calculator, adjust it for your goal, and turn the result into gram targets with the Macro Calculator. This guide explains what to enter at each step, why protein should be set by body weight instead of copied as a percentage, and what a realistic rate of change looks like in either direction.
How Macro Targets Are Built
Every macro plan follows the same four moves, in this order.
- Find maintenance. Maintenance is the calorie intake that holds your weight steady. The TDEE Calculator estimates it from weight, height, age, sex, and activity level with the Mifflin-St Jeor equation, and the BMR Calculator shows the resting portion on its own. The TDEE vs BMR guide explains why TDEE, not BMR, is the base.
- Adjust calories for the phase. Subtract for a cut, add for a bulk. The size of that adjustment is the biggest decision in the plan.
- Set protein in grams per kilogram. Protein is the one macro tied to body weight rather than to calories, so it gets set first and stays roughly fixed across phases.
- Set fat, then give the rest to carbs. Fat has a floor, since essential fatty acids and the fat-soluble vitamins depend on it. Everything left after protein and fat goes to carbohydrate.
The gram conversions are fixed: protein and carbohydrate each carry 4 calories per gram, and fat carries 9. The Macro Calculator accepts a calorie total plus three percentages, so once you know your protein grams you convert them into a share of calories: grams times 4, divided by calories, times 100. A 65 kg person aiming for 2.0 g/kg needs 130 g, which is 520 calories, or about 30.6 percent of a 1,700 calorie day. Round to the nearest whole percent and enter it.
Cut vs Bulk at a Glance
| Target | Cut | Bulk |
|---|---|---|
| Calories | 10 to 25% below maintenance | 10 to 20% above maintenance |
| Protein | 1.6 to 2.2 g/kg, toward the top of the range | 1.6 to 2.2 g/kg, the lower half is usually enough |
| Fat | 0.5 to 1.5 g/kg, or about 20 to 35% of calories | 0.5 to 1.5 g/kg, or about 20 to 35% of calories |
| Carbohydrates | Whatever calories remain, usually the smallest share | Whatever calories remain, usually the largest share |
| Expected weekly weight change | Loss of about 0.5 to 1% of body weight | Gain of roughly 0.25 to 0.5% of body weight |
The sources behind these ranges are named in the next two sections. Treat every row as a starting band to test for a few weeks, not a prescription.
Setting Macros for a Cut
Calories. The contest-preparation review by Helms, Aragon, and Fitschen (2014, Journal of the International Society of Sports Nutrition) recommends losing about 0.5 to 1 percent of body weight per week so that lean mass is protected. For most body sizes, a deficit somewhere between 10 and 25 percent of maintenance lands in that window. The Calorie Deficit Calculator applies a chosen percentage to your estimated maintenance and returns the daily target.
Slower usually wins. Garthe and colleagues (2011, International Journal of Sport Nutrition and Exercise Metabolism) compared athletes losing about 0.7 percent of body weight per week with athletes losing about 1.4 percent. The slower group preserved lean mass better, even though the faster group finished sooner. If you are choosing between a 15 percent and a 30 percent deficit, the evidence leans toward the smaller one.
Protein. Set protein toward the top of the range during a cut. A 2018 meta-analysis by Morton and colleagues in the British Journal of Sports Medicine found that the benefit of extra protein for gaining lean mass with resistance training plateaued around 1.6 g/kg per day, with the upper end of the confidence interval near 2.2 g/kg. The International Society of Sports Nutrition position stand on protein (Jager and colleagues, 2017) recommends 1.4 to 2.0 g/kg for exercising adults and notes that higher intakes may help during calorie restriction. Around 2.0 g/kg is a reasonable cutting default for a resistance-trained person. The Protein Calculator cut setting uses 1.8 g/kg with a planning range that reaches 2.0 g/kg.
Fat. Keep fat off the floor. The off-season review by Iraki and colleagues (2019, Sports) places fat at roughly 0.5 to 1.5 g/kg per day, and the Dietary Reference Intakes from the National Academies set the acceptable range for adults at 20 to 35 percent of calories. On a cut, fat often sits in the lower half of that range so carbohydrates keep some room.
Carbohydrates. Carbs get what is left, which on a cut is the smallest share of the three. That is why training performance can dip late in a long cut. Keep as many carbs as the budget allows once protein and fat are set.
Setting Macros for a Bulk
Calories. A bulk needs a surplus, but not a large one. Iraki and colleagues (2019) recommend eating about 10 to 20 percent above maintenance in the off-season, with the scale climbing roughly 0.25 to 0.5 percent of body weight per week. Slater and colleagues (2019, Frontiers in Nutrition) reviewed how large a surplus muscle growth requires and concluded that a modest one is enough. Past that point, extra calories mostly add fat rather than more muscle. Beginners and people returning after a layoff can usually sit at the top of the range. Experienced lifters tend to do better near the bottom.
Protein. The same 1.6 to 2.2 g/kg range applies, but the lower half is usually enough when calories are already high. The Morton meta-analysis found no extra lean-mass benefit above about 1.6 g/kg, so pushing protein far higher during a bulk mostly displaces carbs. The Protein Calculator build setting uses 1.6 g/kg.
Fat. The same 0.5 to 1.5 g/kg band applies. Many lifters land near the middle of the 20 to 35 percent range on a bulk because the calorie budget has room.
Carbohydrates. This is where the surplus goes. The 2016 joint position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine gives athletes a carbohydrate range of about 3 to 10 g/kg per day depending on training volume. Someone lifting four to six days a week at a surplus usually lands in the middle of that range without trying.
Two Worked Examples
Both examples use the CalcTide tools exactly as they run today, so you can reproduce every number. Maintenance comes from the TDEE Calculator on the Moderate activity setting. The macro grams come from the Macro Calculator with the calorie total and percentages listed.
| Step | Cut: woman, 30, 65 kg, 165 cm | Bulk: man, 24, 72 kg, 178 cm |
|---|---|---|
| Estimated BMR | 1,370 kcal | 1,718 kcal |
| Estimated TDEE (Moderate) | 2,124 kcal | 2,662 kcal |
| Adjustment | 20% deficit, target 1,700 kcal | About 15% surplus, target 3,050 kcal |
| Split entered | 30% protein, 40% carbs, 30% fat | 20% protein, 55% carbs, 25% fat |
| Protein | 127.5 g (1.96 g/kg) | 152.5 g (2.12 g/kg) |
| Carbohydrates | 170 g (2.6 g/kg) | 419.4 g (5.8 g/kg) |
| Fat | 56.7 g (0.87 g/kg) | 84.7 g (1.18 g/kg) |
| Expected weekly change | Lose about 0.33 to 0.65 kg | Gain about 0.18 to 0.36 kg |
Example 1: the cut
The TDEE Calculator gives her a BMR of 1,370 and a maintenance estimate of 2,124 calories. The Calorie Deficit Calculator at 20 percent returns 1,699, which rounds to a planning target of 1,700. Her protein goal is about 2.0 g/kg, or 130 g, and 130 g times 4 is 520 calories, which is 30.6 percent of 1,700. She enters 1700 calories with 30 percent protein, 40 percent carbs, and 30 percent fat. The tool returns 127.5 g protein, 170 g carbs, and 56.7 g fat.
Notice what a copied cutting split would have done. At 40 percent protein the same 1,700 calories would give 170 g, or 2.62 g/kg, more than the research supports, with carbs squeezed down to 127.5 g for no added benefit. The 30 percent share looks like a maintenance split on paper, but it is the number that matches the research range for her body weight.
Example 2: the bulk
The TDEE Calculator gives him a BMR of 1,718 and a maintenance estimate of 2,662 calories. A 15 percent surplus is 3,061, and a planning target of 3,050 keeps the number easy to track. That is 388 calories above maintenance, or about 14.6 percent. His protein goal at 2.0 g/kg is 144 g, or 576 calories, which is 18.9 percent of 3,050. He enters 3050 calories with 20 percent protein, 55 percent carbs, and 25 percent fat. The tool returns 152.5 g protein, 419.4 g carbs, and 84.7 g fat.
Twenty percent protein reads low next to the generic bulking splits, and yet it delivers more protein in grams than the cut does. That is the whole point of setting protein by body weight first. Had he entered 30 percent, the tool would return 228.8 g, or 3.2 g/kg, and the extra 76 g of protein would have come straight out of the carbohydrates fueling his sessions.
Common Mistakes
Copying a percentage split from someone else
A 40/30/30 split is not a cutting plan, and a 25/50/25 split is not a bulking plan. Each is only right at one combination of body weight and calories. Set protein in grams per kilogram first, then convert.
Cutting too hard
A 30 or 40 percent deficit moves the scale fast for two weeks and then tends to stall on hunger, poor sleep, and lost training quality. The Garthe comparison is the clearest evidence that a slower rate protects muscle better.
Bulking as if calories were free
A 500 to 1,000 calorie surplus does not build muscle faster than a 300 calorie one for most trained lifters. It builds fat faster, which lengthens the next cut.
Letting fat drop to almost nothing
Very low fat intakes show up in aggressive cuts. Keep fat at or above roughly 0.5 g/kg, the floor of the off-season review range, unless a clinician has told you otherwise.
Recalculating every week
Body weight can swing by a kilogram or more from one day to the next because of water, sodium, and food volume. Hold a target for three to four weeks, compare the weekly average with the expected rate, and adjust calories by a small step, such as 5 to 10 percent, only if the trend is off. The calorie deficit guide covers how to read that trend.
Limitations
These targets are planning estimates, not measurements. The maintenance number behind every macro plan comes from an equation that can miss by a few hundred calories for any one person, and the activity multiplier is a guess about a whole week. The research ranges above come mostly from studies of resistance-trained adults, many of them men, and they describe averages rather than what any specific person will experience.
Body weight in kilograms is a rough stand-in for lean mass. Someone with a high body-fat percentage may do better setting protein against a goal weight rather than current weight. Medical conditions, pregnancy, medications, a history of disordered eating, and age all change what is appropriate, and none of that is captured by four inputs and three percentages. For the full set of planning tools, see the health calculators hub.
Important Note
This article is educational and estimate-based. It does not provide medical or nutritional advice, diagnosis, or treatment. The ranges described are population averages from sports nutrition research and may not fit your situation. For personal decisions about diet, especially with a health condition, medication, pregnancy, or a history of disordered eating, work with a registered dietitian or another qualified healthcare professional.