How to Calculate Macros for Bulking & Cutting (Step by Step)

How to calculate macros for bodybuilding bulking and cutting? (Quick Answer)

Multiply your bodyweight by 15 for maintenance, add ~300 calories to bulk or subtract ~500 to cut, set protein at 1g per pound, fat at 0.3–0.4g per pound, then fill the rest with carbs. That five-step order works for both phases — only the numbers change.

Lock protein and fat to your bodyweight, let carbs absorb the leftover calories, then weigh your food and adjust by the scale every few weeks. That's the whole system — the rest of this guide shows the math and how to turn it into meals.

How do I calculate my maintenance calories?

Maintenance is the calorie level where your weight holds steady, and every bulk or cut is built off it. The fast estimate beats any online calculator for getting started:

Bodyweight (lbs) × 14–16 = maintenance calories.

Pick your multiplier by activity:

• 14 — desk job, training 0–2 days/week
• 15 — training 3–5 days/week (most lifters)
• 16 — physical job or training 6+ days/week

A 180-lb lifter training 4 days a week: 180 × 15 = 2,700 calories. This is an estimate, not gospel — you'll confirm it with the scale over your first two weeks. If your weight holds at 2,700 for 10–14 days, that number is correct. If it drifts up or down, your true maintenance is higher or lower, and you adjust from there.

For a deeper breakdown using the Mifflin-St Jeor BMR formula and activity multipliers, see how to calculate meal prep portions for your calorie goal.

How many calories for bulking vs cutting?

Once you have maintenance, the adjustment is a single number — and bigger is not better.

For our 180-lb lifter at 2,700 maintenance:

• Lean bulk: 2,700 + 300 = 3,000 calories
• Moderate cut: 2,700 − 500 = 2,200 calories

A 300-calorie surplus builds muscle just as fast as a 700-calorie one — you only differ in how much fat rides along. On a cut, never go below roughly 10–11 calories per pound of bodyweight (about 1,900 for a 180-lb person), or training quality and muscle retention crater.

How do I set my protein when bulking and cutting?

Protein is the macro you anchor first because it protects muscle, and it's the one that changes most between phases.

• Bulking: 0.8–1g per pound. Muscle gain doesn't require sky-high protein when calories are plentiful. At 180 lb, 0.9g/lb = 162g.
• Cutting: 1–1.2g per pound. In a deficit, higher protein preserves muscle and crushes hunger. At 180 lb, 1.1g/lb = 198g.

Protein is 4 calories per gram, so 198g cutting = 792 calories of your daily total spoken for. Spread it across 4 meals at 40–50g each, the amount your body uses most efficiently per sitting. For the full per-bodyweight breakdown, see how much protein to build muscle: grams-per-pound chart.

A digital scale is the only way these numbers mean anything — eyeballing chicken is off by 20–40%. A $15 kitchen scale with a tare button pays for itself in accuracy the first week.

How do I set fat and carbs for each phase?

Fat comes second, carbs come last — carbs are simply whatever calories remain.

Fat (9 calories per gram):

• Bulking: 0.4g per pound → 180 lb = 72g (648 calories)
• Cutting: 0.3–0.35g per pound → 180 lb = 60g (540 calories)

Do not drop fat below 0.3g per pound. Go lower and testosterone, recovery, and mood all decline — the fastest way to ruin a cut. Fat is a hormone floor, not a place to cut corners.

Carbs (4 calories per gram): subtract protein and fat calories from your total, divide what's left by 4.

Bulking math (3,000 cal): 3,000 − 648 (protein) − 648 (fat) = 1,704 ÷ 4 = 426g carbs

Cutting math (2,200 cal): 2,200 − 792 (protein) − 540 (fat) = 868 ÷ 4 = 217g carbs

Carbs are your training fuel and your easiest lever. When progress stalls, you nudge carbs up (bulk) or down (cut) by 25–50g — you never touch the protein floor.

How do I turn macros into actual meal prep?

Macros only work if your containers hit them, and meal prep is built for this: do the math once for a batch, then it carries through every meal. Reference numbers for cooked food (per 100g):

• Chicken breast: 31g protein, 0g carbs, 3.6g fat
• 93/7 ground beef or turkey: 22g protein, 0g carbs, 11g fat
• White rice (cooked): 2.7g protein, 28g carbs, 0.3g fat
• Sweet potato (cooked): 2g protein, 20g carbs, 0g fat
• Olive oil: 0/0/14g fat per tablespoon

For the cutting target (198P / 217C / 60F) across 4 meals, you might prep:

• 640g cooked chicken breast → 160g per meal = ~50g protein each
• 750g cooked rice → ~190g per meal = ~53g carbs each
• 3 tbsp olive oil + toppings spread across meals
• Greek yogurt or a protein shake to top off the last ~40g protein

For the bulking target, you simply scale carbs hard: double the rice, add a banana and oats to breakfast, and drizzle more oil. Same proteins, way more fuel. Use same-size containers so portions stay honest — the container size guide shows which volume fits a 50g-protein bulking meal versus a leaner cutting one.

How often should I adjust my macros?

Set numbers are starting points, not final answers. Track your weight every morning and average it weekly — daily readings swing 2–4 lbs on water alone.

• Bulking: if your weekly average hasn't moved in 2 weeks, add 150g carbs worth of food (~600 calories). Gaining faster than 0.5 lb/week? Pull back 100–150 calories.
• Cutting: if the scale stalls for 2 weeks, cut 150–200 calories (drop carbs first, keep protein). Losing faster than 1.5 lb/week? You're risking muscle — add 150 calories back.

Recalculate your full macros every time bodyweight shifts 5–8 lbs, since maintenance moves with you. Small, patient adjustments beat slashing 800 calories in a panic.

Common Mistakes

• Setting the surplus or deficit too aggressive. A +700 bulk just adds fat; a −800 cut burns muscle and energy. Stay in the 300 / 500 range.
• Dropping fat too low on a cut. Below 0.3g per pound and your hormones tank. Fat is a floor, not a target to minimize.
• Cutting protein during a deficit. Protein should go up when cutting, not down. It's the one macro that saves your muscle.
• Mixing raw and cooked entries. Chicken loses ~25% weight cooking; logging 100g raw against a cooked entry inflates your numbers. Pick one and match the app.
• Adjusting off one day's weight. Water and sodium swing the scale daily. Only act on a 2-week average.
• Forgetting cooking oil. One tablespoon is 14g fat and 120 calories — enough to erase a cut's deficit if it goes unlogged.

Related Guides

• Beginner guides hub — every meal prep basic in one place
• How Much Protein to Build Muscle: Grams-Per-Pound Chart — the protein numbers behind step 3
• Cheap Bulking Meal Prep for Skinny Guys: $3 Per Meal — a done-for-you bulking plan on a budget
• Gym-Day Meal Prep: Pre & Post-Workout in One Plan — timing the carbs you just calculated around training

The Bottom Line

Calculating macros for bulking and cutting is the same five moves every time: find maintenance at bodyweight × 15, adjust by ~300 to bulk or ~500 to cut, anchor protein to your bodyweight (higher when cutting), set fat at 0.3–0.4g per pound as a hormone floor, and let carbs soak up the rest. The numbers are a starting estimate — the scale is the truth. Weigh your food, track your weekly average, and adjust by 150 calories at a time. Get a food scale, save your staple bulk and cut meals once, and the system runs on autopilot through both phases.