By CalcMesh Editorial · Reviewed against primary-source formulas

Macro Calculator

Q: How much protein do I need per day?

A good starting point is 0.7-1g of protein per pound of body weight for active individuals. Endurance athletes may need 0.5-0.65g/lb, while those trying to build muscle benefit from 0.8-1.2g/lb. Sedentary adults can maintain health with as little as 0.36g/lb.

Q: How does body fat percentage affect my macros?

Body fat percentage lets the calculator use the Katch-McArdle formula, which estimates your BMR from lean body mass instead of total weight. This is more accurate for people with high muscle mass or high body fat, since two people at the same weight can have very different caloric needs depending on body composition. If you know your body fat %, enter it for a more precise result.

Q: Should I track macros or just calories?

Tracking macros gives more control over body composition and energy levels. Someone eating 2,000 calories of mostly carbs will have very different results than someone eating 2,000 calories with balanced macros. If you have specific fitness goals, tracking macros is worth the effort.

Q: What are good sources of each macro?

Protein: chicken, fish, eggs, Greek yogurt, legumes, tofu. Carbs: oats, rice, sweet potatoes, fruits, vegetables, whole grains. Fats: avocado, nuts, olive oil, salmon, eggs, dark chocolate. Aim for mostly whole, minimally processed foods.

Q: Do I need to hit my macros exactly every day?

No. Think of macros as weekly averages rather than daily targets. Being within 5-10g of each macro is close enough. Consistency over weeks matters more than precision on any single day. Focus on hitting your protein target first, as it has the most impact on body composition.

Q: What is a good macro ratio for weight loss?

A 40% protein, 30% carbs, 30% fat split works well for most people cutting weight. The higher protein helps preserve muscle while in a calorie deficit. This calculator automatically adjusts macro ratios based on your selected goal — lose weight, maintain, or gain muscle.

Calculate your daily protein, carbs, and fat targets. Add your body fat percentage for a more accurate result using the Katch-McArdle formula.

Gender

Age

years

Height

inches

5'9" = 69 inches

Weight

lbs

Body Fat %

Optional — enables the more precise Katch-McArdle formula

Activity Level

Goal

Daily Calories

—

Target intake

Protein

—

grams per day

Carbs

—

grams per day

Fat

—

grams per day

Using Mifflin-St Jeor formula

Don't know your body fat %? Use our body fat calculator to estimate it first.

Macronutrient Guide

What Are Macros?

Macronutrients are the three nutrients your body needs in large amounts: protein (4 cal/g), carbohydrates (4 cal/g), and fat (9 cal/g). Each plays a distinct role in your body, and the right balance depends on your goals.

How This Calculator Works

This macro calculator estimates your Total Daily Energy Expenditure (TDEE) — how many calories you burn per day — then divides those calories into protein, carbs, and fat based on your goal.

The calculator supports two BMR formulas:

Mifflin-St Jeor (default): Uses height, weight, age, and gender. Accurate for most people with average body composition.
Katch-McArdle (when you enter body fat %): Uses lean body mass, making it more accurate for muscular or obese individuals. BMR = 370 + (21.6 × lean mass in kg).

If you know your body fat percentage, enter it above to switch to the Katch-McArdle formula. Don't know your body fat? Use our body fat calculator to estimate it.

Macro Splits by Goal

Goal	Protein	Carbs	Fat
Weight Loss	40%	30%	30%
Maintenance	30%	40%	30%
Muscle Gain	30%	45%	25%

Why Protein Matters Most

Protein is the most important macro for body composition. It preserves muscle during weight loss, builds muscle during a surplus, and has the highest thermic effect — 20-30% of protein calories are burned during digestion alone. That means eating 100 calories of protein nets you only 70-80 usable calories, making it harder to overeat. Prioritize hitting your protein target above all else.

Why Body Fat Percentage Matters

Two people who weigh 200 lbs can have very different caloric needs. Someone at 15% body fat has significantly more lean mass (and a higher metabolism) than someone at 35% body fat. By entering your body fat percentage, this calculator uses lean body mass to give you a more precise BMR — and therefore more accurate macro targets.

Adjusting Over Time

Track weight weekly (same conditions) for 2-3 weeks before adjusting.
Not losing weight? Reduce calories by 10% (mostly from carbs or fat).
Not gaining? Add 200 calories (mostly from carbs).
Feeling fatigued? You may need more carbs, especially around workouts.
Losing strength? Increase protein to 1g per pound of body weight.

Related Data

Look up nutrition facts, macros, and ingredients for 2M+ foods at USDA FoodData Central. Check supplement and vitamin data at NIH ODS.

Disclaimer: This calculator provides estimates for informational purposes only. Individual needs vary based on genetics, medical conditions, and other factors. Consult a registered dietitian for personalized nutrition advice.

Macronutrients in Real Diets

The Dietary Reference Intakes set the Acceptable Macronutrient Distribution Range at 45-65% carbohydrates, 20-35% fat, and 10-35% protein for adults. NHANES 2017-2020 found actual U.S. intake averaged 47.7% carbs, 36.3% fat, and 16.0% protein — fat intake runs above DRI recommendations for a majority of adults. Saturated fat averaged 11.3% of calories, exceeding the <10% Dietary Guidelines target.

Protein needs scale with body mass and activity. The RDA of 0.8 g/kg/day is the minimum to prevent deficiency but research supports 1.2-2.0 g/kg for active adults and 1.6-2.2 g/kg for resistance-trained lifters (International Society of Sports Nutrition 2017 position stand). A 170 lb (77 kg) adult needs 62 g/day at RDA but up to 170 g/day while building muscle — nearly a 3x range depending on goals.

Ketogenic, Mediterranean, and standard American diets produce meaningfully different macro splits. Keto runs 5-10% carbs / 70-80% fat / 20-25% protein; Mediterranean roughly 50% / 35% / 15%; and the standard American pattern is 48% / 36% / 16% per NHANES. A 2019 JAMA meta-analysis of 48 weight-loss trials (N=7,286) found 12-month weight loss differed by only 1-2 kg between low-carb and low-fat diets — adherence mattered more than composition.

Sources: IOM Dietary Reference Intakes, NHANES 2017-2020, ISSN 2017 position stand, JAMA meta-analysis

Methodology & Assumptions

This calculator implements standard formulas drawn from primary-source authorities. Values are point-in-time estimates; consult a licensed professional for high-stakes decisions. See the per-input definitions and source citations below.

How this works

Computations are deterministic and run client-side — no inputs leave your browser. Formulas are derived from standard published formulas for the calculator's domain (mortgage, taxes, energy, conversions, etc.). When the underlying agency publishes updated rates or thresholds we refresh defaults and update the page's lastmod timestamp.

Frequently Asked Questions

How much protein do I need per day?

A good starting point is 0.7-1g of protein per pound of body weight for active individuals. Endurance athletes may need 0.5-0.65g/lb, while those trying to build muscle benefit from 0.8-1.2g/lb. Sedentary adults can maintain health with as little as 0.36g/lb.

How does body fat percentage affect my macros?

Body fat percentage lets the calculator use the Katch-McArdle formula, which estimates your BMR from lean body mass instead of total weight. This is more accurate for people with high muscle mass or high body fat, since two people at the same weight can have very different caloric needs depending on body composition. If you know your body fat %, enter it for a more precise result.

Should I track macros or just calories?

Tracking macros gives more control over body composition and energy levels. Someone eating 2,000 calories of mostly carbs will have very different results than someone eating 2,000 calories with balanced macros. If you have specific fitness goals, tracking macros is worth the effort.

What are good sources of each macro?

Protein: chicken, fish, eggs, Greek yogurt, legumes, tofu. Carbs: oats, rice, sweet potatoes, fruits, vegetables, whole grains. Fats: avocado, nuts, olive oil, salmon, eggs, dark chocolate. Aim for mostly whole, minimally processed foods.

Do I need to hit my macros exactly every day?

No. Think of macros as weekly averages rather than daily targets. Being within 5-10g of each macro is close enough. Consistency over weeks matters more than precision on any single day. Focus on hitting your protein target first, as it has the most impact on body composition.

What is a good macro ratio for weight loss?

A 40% protein, 30% carbs, 30% fat split works well for most people cutting weight. The higher protein helps preserve muscle while in a calorie deficit. This calculator automatically adjusts macro ratios based on your selected goal — lose weight, maintain, or gain muscle.