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Macro Calculator

A macro calculator breaks your daily calorie target down into the three macronutrients your body uses for energy: protein, carbohydrates and fat. While total calories determine whether you lose, gain or maintain weight, your macro split determines how much of that weight change comes from muscle versus fat. Getting your macros right means you are not just hitting a calorie number, you are making sure those calories are doing the right job. Enter your stats and goal below to get your personalized macro targets.

What Are Macros?

Macros, short for macronutrients, are the three main nutrients your body uses to produce energy: protein, carbohydrates and fat. Every food you eat is made up of some combination of these three, and each one plays a distinct role in how your body functions and how your physique changes over time.

Protein is the building block of muscle tissue. It is also the most important macronutrient for body composition because it supports muscle growth, helps preserve muscle during a calorie deficit and keeps you fuller for longer than carbs or fat at the same calorie load.

Carbohydrates are your body's preferred fuel source, particularly during intense exercise. They are stored in your muscles and liver as glycogen and drawn on during training. Carbs are not essential in the way protein and fat are, but for most active people they support performance and recovery in ways that are difficult to replicate.

Fat is essential for hormone production, joint health and the absorption of fat-soluble vitamins. Unlike carbs, dietary fat is required for basic biological function. Dropping fat too low has real consequences, which is why a minimum fat intake is always set before carbs are calculated.

All three macros contain calories: protein and carbohydrates each provide 4 calories per gram, while fat provides 9 calories per gram. This is why fat takes up a larger share of your calorie budget relative to its gram weight compared to the other two.

How to Calculate Your Macros

Calculating your macros is a three-step process. The calculator handles all of this automatically, but understanding the logic behind it helps you make better adjustments over time.

Step 1: Find your calorie target. Your macro split is built on top of a calorie target, which is based on your Total Daily Energy Expenditure (TDEE). Your TDEE is the number of calories your body burns in a day. Depending on your goal, you will eat below, at or above that number. Use the Built With Science TDEE calculator if you want to see that number in detail before setting your macros.

Step 2: Set your protein. Protein is always calculated first. Aim for 0.7–1 gram of protein per pound of body weight. This range covers the needs of most people, from those in a calorie deficit trying to preserve muscle to those in a surplus trying to maximize muscle growth. At 4 calories per gram, this gives you your protein calorie total.

Step 3: Set your fat, then fill with carbs. Set fat at around 25–30% of your total daily calories for hormonal health and general wellbeing. Convert that to grams by dividing by 9. Whatever calories remain after protein and fat are accounted for go to carbohydrates. Divide those remaining calories by 4 to get your carb gram target.

How Much Protein Do You Need?

Protein is the macro that matters most for body composition, and it is the one most people consistently undereat. The research is clear: higher protein intakes preserve more muscle during fat loss and support more muscle growth during a surplus compared to lower protein intakes at the same total calorie level.

For most people, a target of 0.7–1 gram of protein per pound of body weight covers the full range of needs. Leaner individuals and those in a calorie deficit should aim toward the higher end of that range, since preserving muscle becomes harder as body fat decreases and calorie intake drops. Those in a surplus with more body fat to lose can often do well at the lower end.

If you are struggling to hit your protein target through whole foods alone, a high-quality whey protein supplement is one of the most practical ways to close the gap without significantly increasing your overall calorie intake.

One important note: protein recommendations are based on your current body weight, not your goal weight. If you are carrying a significant amount of excess body fat, using your goal body weight or a lean body mass estimate as the basis for your protein target is more appropriate.

If your main goal is fat loss, remember that macros are only one part of the process. For the full picture — including training, calorie control and how to preserve muscle while dieting — see our guide on how to lose body fat.

How to Set Your Carbs and Fat

Once protein is set, the remaining calories are split between fat and carbohydrates. Fat is set first because it has a physiological floor that carbohydrates do not.

Fat: Set fat at 25–30% of your total daily calories. Going below this range consistently can impair hormone production, particularly testosterone and estrogen, and reduce the absorption of fat-soluble vitamins A, D, E and K. The exact percentage within this range is flexible and can be adjusted based on personal preference and food choices. Some people feel and perform better with slightly higher fat intakes, particularly those following lower-carb approaches.

Carbohydrates: Fill the remaining calories with carbohydrates. Carbs are the most flexible of the three macros and the appropriate amount varies significantly depending on your total calorie target, your activity level and your personal preference. Someone eating 2,400 calories with high protein and adequate fat might have 200–250 grams of carbs available. Someone eating 1,600 calories with the same protein target might have significantly less.

It is worth noting that the carb and fat split can be adjusted within reason based on what works best for you individually, as long as protein stays at target and fat stays above the minimum threshold. Hitting your total calorie and protein targets consistently will account for the vast majority of your results. Once your macro targets are set, you can also calculate your water intake so your daily nutrition targets account for both food and fluids.

How This Calculator Works

This macro calculator starts with your TDEE, estimated using a formula based on the Katch-McArdle equation. Unlike standard formulas that use only weight, height, age and gender, Katch-McArdle factors in your lean body mass, which is your total weight minus your body fat. This makes it more accurate for people who carry more or less muscle than average, since muscle tissue burns significantly more calories at rest than fat tissue does.

From your TDEE, the calculator applies an adjustment based on your goal. For fat loss, it applies a moderate calorie deficit. For muscle gain, it applies a controlled calorie surplus. For maintenance, it uses your TDEE directly. If your goal is to lose fat and build muscle at the same time, the body recomposition calculator may give you a more specific starting point.

Once your calorie target is set, the calculator builds your macro split using the methodology outlined above: protein is set first based on your body weight, fat is set at a percentage of total calories, and carbohydrates fill the remainder.

The result is a complete daily macro target that reflects your individual body composition, your activity level and your goal, rather than a generic one-size-fits-all split.

As with any calculator, treat the output as a starting point. Track your intake and your body weight for 2–3 weeks and adjust based on real-world results. The calculator gets you in the right range. Consistent tracking dials it in.

Once your nutrition targets are set, you can pair them with the 1RM calculator to estimate your max strength and choose more appropriate working weights for your main lifts.

MACRO CALCULATOR FAQ

Macros, short for macronutrients, are the three nutrients your body uses to produce energy: protein, carbohydrates and fat. Every food you eat contains some combination of the three. Protein supports muscle growth and repair. Carbohydrates fuel exercise and daily activity. Fat supports hormone production and vitamin absorption.

All three contribute calories to your diet: protein and carbs provide 4 calories per gram, while fat provides 9 calories per gram.
Calories determine whether you lose, gain or maintain weight. Macros determine the quality of that change. Two people eating the same number of calories can have very different body composition outcomes depending on how those calories are distributed. 

Someone eating adequate protein while in a calorie deficit will lose significantly less muscle than someone eating the same deficit with low protein. Macros give you control over not just how much weight you lose or gain, but what that weight is made of.
Start by finding your calorie target for fat loss, which is your TDEE minus a deficit of 300–500 calories per day. If you want a clearer breakdown of how that deficit is set, this guide on how to calculate your calorie deficit explains how to choose a target that is aggressive enough to work without being so steep that it compromises training, recovery or muscle retention.

Then set protein at 0.7–1 gram per pound of body weight, prioritizing the higher end of that range since preserving muscle becomes harder in a deficit. Set fat at 25–30% of your total calories. Fill the remaining calories with carbohydrates. The calculator above handles all of this automatically once you select fat loss as your goal, but you can also use the calorie calculator as another quick way to estimate your daily calorie and macro targets.
Start with your TDEE and add a surplus of 200–300 calories per day. Set protein at 0.7–1 gram per pound of body weight. Set fat at 25–30% of total calories. Fill the remaining calories with carbohydrates.

The calorie surplus combined with adequate protein gives your body the raw materials it needs to build muscle. Going much higher than 300 calories above your TDEE does not accelerate muscle growth. It mainly adds body fat.
For most people, 0.7–1 gram of protein per pound of body weight is the right target. This range covers the needs of people in a fat loss phase, a muscle building phase and everything in between. If you are leaner or deeper into a calorie deficit, aim toward the higher end. If you are in a surplus with more body fat to lose, the lower end is typically sufficient.

If your body weight is significantly above your goal weight, base your protein target on your goal weight or an estimate of your lean body mass rather than your total body weight.
Set fat at 25–30% of your total daily calories. This range supports hormone production, vitamin absorption and general health. Going consistently below this threshold can impair testosterone and estrogen levels and reduce your ability to absorb fat-soluble vitamins A, D, E and K.

Within the 25–30% range, the exact amount is flexible. Some people feel better with slightly higher fat intakes, particularly those who prefer fewer carbohydrates.
Carbohydrates fill whatever calories remain after protein and fat are set. For most active people this works out to roughly 40–50% of total daily calories, though the exact amount depends on your total calorie target and how much protein and fat you are eating.

Carbs are the most flexible of the three macros. If you prefer a lower-carb approach, you can shift some carb calories to fat as long as protein stays at target and fat stays above the minimum threshold.
No. Hitting your macros exactly every single day is neither necessary nor realistic for most people. What matters is consistency over time. If you are hitting your calorie and protein targets most days, the precise carb and fat split matters far less.

A useful way to think about it: calories and protein are non-negotiable targets to hit as consistently as possible. Carbs and fat are more flexible and can shift day to day based on food choices as long as the weekly averages are close to your targets.
Focus on building meals around protein sources first. Eggs, chicken, fish, Greek yogurt, cottage cheese and lean beef are all high-protein foods that make it easier to hit your target without pushing your calories too high.

If you are still falling short, a high-quality whey protein supplement is one of the most practical ways to close the gap. One or two scoops per day can add 50–100 grams of protein with minimal impact on your overall calorie budget.
Calories measure total energy intake. Macros describe where those calories come from. Every gram of protein and carbohydrate contributes 4 calories. Every gram of fat contributes 9 calories.

Tracking macros is a more detailed version of tracking calories. It tells you not just how much energy you are consuming but whether that energy is coming from the right sources for your goal. For most people, getting calories right produces most of the result. Getting macros right, particularly protein, refines and improves that result.
Neither is inherently more important than the other for body composition, as long as fat stays above the minimum threshold for hormonal health. The right balance depends on your personal preference, your food choices and how you feel during training.

People who train at high intensities often perform better with higher carb intakes since carbohydrates are the primary fuel source during intense exercise. People who prefer fewer carbohydrates can shift more calories to fat without meaningful differences in body composition outcomes, provided protein and total calories stay on target.
Track your body weight and how you feel for 2–3 weeks after setting your macros.

If your weight is not moving in the expected direction, adjust your total calorie intake first by 100–200 calories in the appropriate direction. If your weight is moving as expected but you are losing strength or feeling consistently fatigued, consider increasing protein slightly or checking whether total calories are too low.

Macro adjustments should follow calorie adjustments, not precede them. Get calories right first, then fine-tune the split.
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