How to Calculate Your Macros for Weight Loss or Muscle Gain

To calculate your macros: estimate your total daily energy expenditure (TDEE) with the Mifflin-St Jeor equation, adjust calories for your goal (subtract about 500 a day for weight loss, add 250–500 for muscle gain), set protein first at 0.65–1.35 g per pound of bodyweight, give fat 20–35% of calories, and fill what's left with carbs.

That's the whole method. The reason to learn it, instead of letting a calculator hand you numbers, is that the numbers stop working eventually. Weight loss stalls. The scale refuses to move on a bulk. When that happens, people who know the math adjust one variable and keep going; people who don't go hunting for a new calculator and start the whole guessing game over.

The three numbers everything else is built on

Protein has 4 calories per gram. Carbohydrates have 4. Fat has 9. Memorize those, because every step below is just these three numbers plus arithmetic: grams times calories-per-gram gives you calories, and calories divided by calories-per-gram gives you grams. Once you can flip between the two, you can rebuild your entire plan on the back of a receipt.

Step 1: Find your maintenance calories (TDEE)

TDEE is what you burn in a normal day, and everything else hangs off it. Start with basal metabolic rate (BMR), the calories your body burns just existing, using the Mifflin-St Jeor equation. It's the formula most dietitians default to, accurate within roughly 5 percent for most people:

• Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
• Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

Pounds divided by 2.2 gives you kilograms; inches times 2.54 gives you centimeters. Then multiply BMR by an activity factor to get your TDEE:

One warning before you pick a row: almost everyone chooses a tier too high. More on that below.

Step 2: Set your calories for the goal

For weight loss, subtract about 500 calories a day from TDEE. That produces roughly a pound of fat loss per week, which is about the fastest most people can lose while keeping their training performance and their sanity intact. Cutting harder feels productive for two weeks and then backfires: your energy craters and the diet ends at a drive-thru. If you want a bigger deficit, earn it with movement rather than a 1,200-calorie plan.

For muscle gain, add 250 to 500 calories over TDEE. Muscle is slow to build and a bigger surplus doesn't speed it up; the extra just gets stored as fat you'll have to diet off later. Beginners can sit near the top of that range, experienced lifters near the bottom.

Happy with your weight but want to look different at the same number? Eat right at TDEE and push protein to the high end of the range in the next step.

Step 3: Set protein first (yes, before the ratio)

Here's the stance this whole guide is built on: protein is not one slice of a pie chart. It's a fixed target you set in grams, before anything else, and everything else flexes around it. Ratio-based calculators treat protein as a percentage of calories, which means your protein drops every time you cut calories. That's exactly backwards. In a deficit, protein matters more, not less, because it's the main thing standing between you and losing muscle along with the fat.

• 0.65–0.8 g per pound of bodyweight: general health, lighter activity
• 0.8–1.0 g per pound: fat loss while training, the sweet spot for most gym-goers
• 1.0–1.35 g per pound: muscle gain, hard training, or cutting when you're already lean

Research puts the plateau for muscle building around 0.73 g per pound (1.6 g per kg). Going higher mostly buys insurance, and insurance is cheap when you're dieting. I treated protein as an afterthought on my first cut, hit my calorie target dutifully, and lost fifteen pounds, a noticeable chunk of which was muscle I then spent a year rebuilding. Pin the protein first.

In practice, a target like 170 g means anchoring every meal around 30 to 45 g of protein instead of trying to catch up with a shake at 9pm. For a picture of what an anchored meal looks like, the Smoky Chipotle Shrimp & Lime Rice Bowl on Tasteables runs 40 g in a single serving.

Step 4: Give fat a floor, then hand carbs whatever's left

Fat gets 20 to 35 percent of your total calories; divide by 9 for grams. Don't sit below 20 percent for more than a few weeks. Fat is raw material for hormone production, and very-low-fat plans are also joyless, which becomes its own compliance problem. Whatever calories remain after protein and fat go to carbs, divided by 4. Carbs aren't the enemy here — they fuel your training, and training is what tells your body to keep muscle while the calorie deficit does the fat-burning.

If you like ratio charts as a sanity check: weight-loss plans commonly land near 40/40/20 carbs/protein/fat, with workable ranges of roughly 25–45 percent carbs, 35–50 percent protein, and 20–35 percent fat. Muscle-gain plans sit closer to 45/35/20. But notice the direction of the method: with grams-first math, your percentages fall out at the end. You don't pick them, you check them, and landing a little outside a chart is fine. Our example below comes out at 32 percent protein and works.

The full worked example: 170 lb, moderately active, losing fat

Meet the test case: a 35-year-old man, 5'10" (178 cm), 170 lb (77 kg), training three or four days a week, who wants to lose fat.

1. BMR: (10 × 77) + (6.25 × 178) − (5 × 35) + 5 = 770 + 1,112.5 − 175 + 5 = 1,713 calories
2. TDEE: 1,713 × 1.55 (moderately active) = 2,655. Call it 2,650.
3. Goal calories: 2,650 − 500 = 2,150 per day
4. Protein: 1.0 g/lb × 170 lb = 170 g = 680 calories
5. Fat: 25% of 2,150 = 540 calories ÷ 9 = 60 g
6. Carbs: 2,150 − 680 − 540 = 930 calories ÷ 4 = 232 g

His finished split is roughly 43/32/25, close to the classic weight-loss templates without ever choosing one. The next practical question is how to spread 2,150 calories across the day, which is its own decision; How Many Calories Should Each Meal Be? walks through it.

Where people go wrong

They flatter their activity level

This is the most common failure by a wide margin. Three gym sessions a week on top of a desk job is moderately active at best, and if those workouts run 40 minutes, lightly active is closer to the truth. The diagnostic sign: you're supposedly in a deficit and the scale hasn't budged in three weeks. Your deficit is fictional. Recalculate one tier down and the math starts working again.

They cut fat to nothing

On a 2,150-calorie plan, 15 percent fat is about 36 g a day. That's one avocado and a drizzle of olive oil, total, and nobody sustains it. Hold the 20 percent floor even when it means fewer carbs than you'd like.

They never update the numbers

The TDEE you calculated at 190 lb is wrong at 175 lb, because a smaller body burns less. Rerun the math every 10 pounds of change in either direction, or your deficit quietly shrinks toward zero and you'll blame the method instead of the arithmetic.

When to adjust (and when to sit on your hands)

Give any set of numbers two full weeks before judging it. Daily scale weight is mostly noise from water, sodium, and yesterday's carbs, so compare weekly averages instead of mornings.

If your weekly average hasn't moved in two or more weeks, change one thing: drop 100 to 200 calories, taken from carbs or fat and never from protein, or add 15 to 20 minutes of brisk walking a day, which is the same size lever and usually more pleasant than eating less. Pick one, run it for two more weeks, then reassess. If you're gaining faster than about half a pound a week on a bulk, trim the surplus by the same 100 to 200.

The calculation itself is a one-time job; twenty minutes and you're done. The daily work is turning 170 g of protein and 2,150 calories into actual meals, and that part is worth automating. Tasteables builds 2–6 day meal plans matched to your calorie level and your macro targets, shows calories and macros on every recipe, and generates the shopping list for you, so the plan you just calculated becomes food without a spreadsheet. If you'd rather run it by hand, How to Meal Prep for a Week Without Eating the Same Thing Every Day will keep it from getting boring. Either way, protein first.

Frequently Asked Questions

Do I need to hit my macros exactly every day?

No. Staying within about 10 g of your protein target and within 5 percent of your calorie target counts as a hit. Your body responds to the weekly average, not any single day, so a Tuesday that runs 40 g of carbs over is noise. Chasing exact numbers usually ends in burnout.

Are macros more important than calories?

Calories decide whether you gain or lose weight; macros decide what that change is made of. A deficit with low protein loses muscle along with fat. So calories come first for the direction, protein second for body composition, and the carb-fat split is a distant third for most people.

How does alcohol count toward macros?

Alcohol has 7 calories per gram and doesn't fit any macro, so count it against your carb or fat budget. A 5 oz glass of wine is roughly 120 calories, which you'd log as about 30 g of carbs or 13 g of fat. Track it somewhere, because ignored drinks are how deficits quietly disappear.

Should my macros change on rest days?

For most people, no. Keeping the same targets every day is simpler and works fine, since muscle repair continues on rest days and protein needs stay high. Carb cycling, meaning more carbs on training days and fewer on rest days, can help serious athletes, but it adds complexity most beginners don't need.

Tasteables turns the ingredients you already have into personalized recipes and weekly meal plans — calories, macros, and shopping list included. Try it free.