How to Set Your Macros for Cutting

TL;DR: Set protein at 1.0g per pound of bodyweight (the single most important macro for muscle preservation), fat at 25-30% of total calories (minimum 0.3g/lb for hormonal health), and carbs from whatever calories remain. Size your deficit based on the Alpert limit. Use our free cut calculator to get your exact numbers.

Setting macros for a cut is not about picking a random calorie number and eating less. Each macronutrient has a specific role during a deficit, and getting the split wrong is the difference between losing fat and losing muscle.

Step 1: Determine Your Deficit Size

Before setting macros, you need to know how many total calories you are working with. Start with your TDEE and subtract your deficit.

The size of your deficit should be proportional to your body fat. The Alpert limit establishes that your body can oxidize approximately 22 kcal per pound of fat mass per day. Exceed this, and the extra energy has to come from muscle tissue.

Example:

180 lb male at 20% body fat = 36 lbs of fat mass
Maximum deficit: 36 x 22 = 792 cal/day
Recommended deficit (70% of max for safety margin): ~555 cal/day

As you get leaner, your maximum sustainable deficit shrinks. A 180 lb male at 12% body fat (21.6 lbs of fat) can only sustain a 475 cal/day deficit without muscle loss.

| Body Fat % | Fat Mass (180 lb) | Max Deficit | Safe Deficit (70%) | |------------|-------------------|-------------|-------------------| | 25% | 45 lbs | 990 cal | 693 cal | | 20% | 36 lbs | 792 cal | 555 cal | | 15% | 27 lbs | 594 cal | 416 cal | | 12% | 21.6 lbs | 475 cal | 333 cal |

Don't want to do this math? Our cut calculator handles all of it.

Step 2: Set Protein (The Most Important Macro)

During a calorie deficit, protein does three critical things:

Preserves muscle mass. Amino acids from dietary protein provide the building blocks to maintain muscle when your body is in a catabolic state.
Has the highest thermic effect. Your body burns ~25% of protein calories during digestion, compared to ~8% for carbs and ~3% for fat. This effectively makes protein "cheaper" calorie-wise.
Increases satiety. Protein is the most filling macronutrient, gram for gram. Higher protein diets reduce hunger during a deficit.

Target: 1.0g per pound of bodyweight.

This is the upper end of the evidence-based range, but during a cut you want to err on the high side. Research by Helms et al. recommends 1.0-1.4g/lb for natural bodybuilders during contest prep. For a recreational lifter on a moderate cut, 1.0g/lb covers your bases.

For a 180 lb person: 180g protein = 720 calories from protein.

If you are significantly overweight (above 30% body fat), use your lean body mass or target bodyweight instead. A 250 lb person at 35% body fat does not need 250g of protein. Use 180g (based on estimated lean mass of ~162 lbs, rounded up).

Step 3: Set Fat (Hormonal Floor)

Dietary fat is essential for hormone production, cell membrane integrity, and absorption of fat-soluble vitamins. During a cut, you need a minimum amount to keep these systems functioning.

Target: 25-30% of total calories, with a floor of 0.3g/lb bodyweight.

For a 180 lb person cutting at 2,200 calories:

25% of 2,200 = 550 calories from fat = 61g
30% of 2,200 = 660 calories from fat = 73g
Minimum floor: 0.3 x 180 = 54g

The 25-30% range is a good balance. Going below 20% of calories from fat can impair testosterone and estrogen production, which directly sabotages your ability to maintain muscle and recover from training.

Types of fat to prioritize:

Monounsaturated: Olive oil, avocado, nuts
Omega-3s: Fatty fish, fish oil, flaxseed
Limit but do not eliminate saturated fat

Step 4: Set Carbs (The Remainder)

After protein and fat are set, all remaining calories go to carbohydrates. Carbs are the "flex" macro during a cut because they have the least direct impact on muscle preservation and hormone production.

Calculation:

Total calories minus protein calories minus fat calories = carb calories
Carb calories divided by 4 = grams of carbs

Example for 180 lb person cutting at 2,200 cal:

| Macro | Grams | Calories | % of Total | |-------|-------|----------|-----------| | Protein | 180g | 720 cal | 33% | | Fat | 67g | 603 cal | 27% | | Carbs | 219g | 877 cal | 40% | | Total | | 2,200 cal | 100% |

This gives a roughly 40/33/27 carb/protein/fat split, which is a common and well-researched cutting macro ratio.

Step 5: Time Your Carbs Around Training

When total carbs are limited, placing them strategically can improve training performance:

Pre-workout (1-2 hours before): 30-50g carbs. Provides glycogen for the training session.
Post-workout: 40-70g carbs. Replenishes glycogen and supports recovery.
Other meals: Distribute remaining carbs evenly or place them where you enjoy them most.

Carb timing is a minor optimization. Getting your total daily carbs right matters far more than when you eat them. But if your training is suffering on a cut, shifting more carbs around your workout can make a noticeable difference.

Common Cutting Macro Mistakes

Protein too low. This is the number one mistake. People cut calories by reducing all macros equally, losing 30-40% of their protein. Protein should be the last macro you cut.
Fat too low. Going below 20% of calories from fat to "save calories for carbs" tanks your hormones. You will feel terrible and your recovery will suffer.
Deficit too aggressive. A 1,000+ calorie deficit at 15% body fat guarantees muscle loss. Size your deficit to your fat mass.
Not adjusting macros as weight drops. As you lose weight, your TDEE decreases. Recalculate every 2-4 weeks or when weight loss stalls for 2+ weeks.
Eliminating food groups. You do not need to cut out all sugar, bread, or dairy. You need to hit your macro targets. How you fill those targets is flexible.

Get Your Exact Cutting Macros

Our free cut calculator uses the Alpert limit and Mifflin-St Jeor equation to calculate your personalized deficit, macro split, and projected timeline. Plug in your stats and get exact numbers in seconds.

Then track those macros with Protokl. AI meal photo logging makes it easy to verify you are hitting your protein target without spending 15 minutes per meal searching a food database. Snap a photo, review the macros, and move on.