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Muscle Gain Macro Calculator
Building muscle needs two things from your diet: a small calorie surplus and enough protein. Research backed guidance points to roughly 1 gram of protein per pound of body weight per day and a 5 to 15 percent surplus over maintenance, with the remaining calories split between carbs for training fuel and fat for hormone health. This muscle gain macro calculator takes your weight, your maintenance calories (TDEE), and your chosen surplus size, then returns your daily calorie target with protein, carb, and fat grams.
How to use
- Enter your weight in pounds.
- Enter your maintenance calories (TDEE). If you do not know it, calculate it with a TDEE calculator first.
- Pick a surplus: 5 percent lean, 10 percent moderate, or 15 percent aggressive.
- Click Calculate to get your daily target with protein, carb, and fat grams.
The math behind the calculator
The calculator does four steps. First, your daily target equals your maintenance calories (TDEE) multiplied by 1 plus your surplus: a 2,600 calorie maintenance with a 10 percent surplus becomes 2,860 calories. Second, protein is set at 1 gram per pound of body weight. Third, fat gets 25 percent of total calories divided by 9 calories per gram. Fourth, carbs get whatever calories remain, divided by 4 calories per gram.
Worked example for a 180 lb lifter at 2,600 maintenance with a 10 percent surplus: 2,860 calories per day, 180 g protein, 79 g fat, and about 357 g carbs. If you know your maintenance is off, fix that number first, because every result downstream depends on it.
How to adjust after 2 to 4 weeks
Weigh yourself each morning and compare weekly averages, not single days, since water weight swings wildly. If the average climbs faster than 0.5 percent of body weight per week for three weeks, trim 100 to 200 calories. If it is flat for three weeks, add 100 to 200.
Keep protein steady while you adjust; change the surplus through carbs and fat. This two week calibration loop is what separates a lean bulk from slow fat gain, because no calculator knows your metabolism as well as your own scale trend does.
Frequently asked questions
How big should my calorie surplus be?
A 5 to 10 percent surplus supports muscle growth with minimal fat gain for most lifters, which is the classic lean bulk. Beginners can push toward 15 percent since they build muscle faster. Bigger surpluses add fat faster than muscle, so more food is not automatically better.
How much protein do I need for muscle gain?
About 1 gram per pound of body weight per day covers most lifters, which matches the research range of 1.6 to 2.2 grams per kilogram. Eating more than that rarely adds benefit once training and total calories are in place.
How should I split carbs and fat?
Protein and total calories matter most. Carbs fuel hard training, so keep them moderate to high. Keep fat at or above 0.3 grams per pound for hormone health. The exact split between the two is flexible and mostly personal preference.
How fast should the scale move?
Aim for 0.25 to 0.5 percent of body weight per week. Realistic monthly gains look like this: beginners 1.5 to 2.5 lb, intermediates 0.75 to 1.25 lb, advanced lifters 0.25 to 0.5 lb. Faster gains are mostly fat, not muscle.
What if I am gaining weight too fast?
Trim the surplus by 100 to 200 calories per day and reassess after two to three weeks. Recalibrate every 2 to 4 weeks: if the weekly average is climbing faster than 0.5 percent of body weight, eat a little less; if it is flat for three weeks, add a little.
Do I need to hit my macros exactly every day?
No. Weekly averages matter far more than any single day. Prioritize protein and total calories; small daily misses on carbs and fat will not ruin progress as long as the trend is right.
Can beginners build muscle without a surplus?
Yes. Beginners and returning lifters can recomp, building muscle while losing fat, at maintenance calories with high protein and good training. A small surplus still builds muscle faster, which is what this calculator targets.
Is this medical advice?
No. These are general fitness nutrition estimates, not medical advice. If you have diabetes, kidney issues, or any medical condition, check with a doctor or registered dietitian before changing your diet.