Macro Calculator

Q: What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep you alive. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. TDEE includes all the calories you burn from exercise, walking, and daily movement on top of your BMR.

Q: Which BMR formula should I use?

For most people, Mifflin-St Jeor is the best choice. A systematic review found it the most reliable of the common equations. 6 Use Katch-McArdle only if you know your body fat percentage, especially if you are lean or athletic. Harris-Benedict is the classic formula; in the Mifflin-St Jeor study its original equations overestimated measured resting energy expenditure by 5%. 1

Q: What diet profile is best for building muscle?

The High Protein profile (40% protein, 35% carbs, 25% fat) is a good choice for building muscle. It gives you plenty of protein to repair and grow muscle tissue, plus enough carbs to fuel your workouts. Pair this with a Slow Gain or Gain Weight goal to make sure you are eating enough calories to support muscle growth.

Level	Multiplier	Description
BMR	1.0	No activity; total rest
Sedentary	1.2	Little or no exercise; desk job
Lightly Active	1.375	Light exercise 1–3 days/week (15–30 min sessions)
Moderately Active	1.465	Moderate exercise 3–5 days/week (30–45 min sessions)
Active	1.55	Active exercise 5+ days/week (45–120 min sessions)
Very Active	1.725	Hard exercise 6–7 days/week or physical job
Extra Active	1.9	Very hard exercise, training 2+ hours/day

Nutrient	Daily Target (g)	Calories	% of Total	Per Meal (3 meals)	Per Meal (4 meals)	Per Meal (5 meals)
Protein	184g	734 kcal	30%	61g	46g	37g
Carbs	245g	979 kcal	40%	82g	61g	49g
Fat	82g	734 kcal	30%	27g	20g	16g
Total	510g	2,448 kcal	100%	170g	128g	102g

Nutrient

Daily Target (g)

Calories

% of Total

Per Meal (3 meals)

Per Meal (4 meals)

Per Meal (5 meals)

Protein

184g

734 kcal

30%

61g

46g

37g

Carbs

245g

979 kcal

40%

82g

61g

49g

Fat

82g

734 kcal

30%

27g

20g

16g

Total

510g

2,448 kcal

100%

170g

128g

102g

Introduction

A macro calculator helps you figure out how many grams of protein, carbs, and fat you should eat each day. These three nutrients are called macronutrients, or "macros" for short. Your body needs all three to stay healthy, build muscle, and have energy. The right balance of macros depends on things like your age, weight, height, activity level, and goals. Whether you want to lose weight, gain muscle, or just eat better, knowing your macros is a great place to start. Use this macro calculator to get a personalized daily breakdown that fits your needs.

How to Use Our Macro Calculator

Enter your personal details and preferences below, and this calculator will give you a daily calorie target along with the exact grams of protein, carbs, and fat you should eat each day.

Sex: Select whether you are male or female. This matters because men and women burn calories at different rates, which changes your macro needs.

Unit System: Choose US/Imperial (pounds, feet, and inches), Metric (kilograms and centimeters), or Other. If you pick "Other," a built-in unit converter will appear so you can convert between units like stone, meters, or inches and then apply those values to the calculator.

Age: Enter your age in years (between 15 and 100). Your body burns fewer calories as you get older, so age plays a key role in finding your correct macros.

Height: Enter your height in feet and inches if using Imperial, or in centimeters if using Metric. Your height helps the calculator figure out your base metabolic rate.

Weight: Enter your current body weight in pounds (Imperial) or kilograms (Metric). This is one of the biggest factors in determining how many calories and macros you need each day.

Activity Level: Pick the option that best describes how active you are on a typical week. Choices range from Sedentary (little or no exercise) all the way up to Extra Active (very hard exercise for two or more hours a day). A higher activity level means your body needs more calories and macros.

Fitness Goal: Choose what you want to do with your weight. You can pick Lose Weight (−500 calories per day), Slow Lose (−250), Maintain (no change), Slow Gain (+250), or Gain Weight (+500). The calculator will adjust your calorie target up or down based on your choice.

Diet Profile: Select a diet style that fits how you like to eat. Options include Balanced (30/40/30 split), Low Carb, High Protein, Keto, Low Fat, or Custom. If you choose Custom, you can type in your own protein, carbs, and fat percentages. Just make sure they add up to 100%.

Settings (BMR Formula): Click the Settings link to choose which formula the calculator uses to estimate your base metabolic rate. Mifflin-St Jeor is the default and works well for most people. Katch-McArdle is better if you know your body fat percentage, and Harris-Benedict is the classic formula. If you pick Katch-McArdle, a body fat percentage field will appear for you to fill in.

Body Fat % (optional): This field only shows up when you select the Katch-McArdle formula under Settings. Enter your body fat percentage (between 1% and 60%) for a more accurate calculation, especially if you are lean or athletic. If you're unsure of your body fat level, our Lean Body Weight Calculator can help you estimate your lean mass.

Once everything is filled in, click Calculate Macros to see your daily calorie target, your protein, carbs, and fat in grams, a visual breakdown chart, and a detailed table that splits your macros across 3, 4, or 5 meals per day. Click Reset at any time to return all fields to their default values.

What Are Macros?

"Macros" is short for macronutrients, the three main nutrients your body needs in large amounts every day to function properly. They are protein, carbohydrates, and fat. Every food you eat is made up of some mix of these three nutrients, and each one plays a different role in keeping you healthy.

Protein (4 calories per gram) builds and repairs muscles, skin, hair, and other tissues.⁷ It also helps you feel full after eating.
Carbohydrates (4 calories per gram) are your body's main source of energy.⁷ Carbs fuel your brain, muscles, and organs throughout the day.
Fat (9 calories per gram) supports hormone production, protects your organs, and helps your body absorb important vitamins like A, D, E, and K.⁷

How a Macro Calculator Works

A macro calculator figures out how many grams of protein, carbs, and fat you should eat each day based on your personal details. It starts by estimating your Basal Metabolic Rate (BMR), the number of calories your body burns at rest just to stay alive (breathing, pumping blood, etc.). Then it multiplies your BMR by an activity level to find your Total Daily Energy Expenditure (TDEE), which is the total number of calories you burn in a full day including exercise and movement.

Once your TDEE is calculated, the tool adjusts the number up or down based on your goal. If you want to lose weight, it subtracts calories. If you want to gain weight, it adds calories. Finally, it splits those calories into protein, carbs, and fat based on the diet profile you choose.

BMR Formulas Explained

There are several well-known formulas used to estimate BMR. The Mifflin-St Jeor equation is the default here because a systematic review found it the most reliable of the common equations.⁶ The Harris-Benedict equation is the classic formula, first published in 1918.² This calculator uses the coefficients from Roza and Shizgal's 1984 re-fit,³ as printed in a 2021 systematic review of prediction equations.⁴ In the Mifflin-St Jeor study the original Harris-Benedict equations overestimated measured resting energy expenditure by 5%.¹ The Katch-McArdle formula is different because it uses your lean body mass (your weight minus your body fat) instead of just your total weight. The equation, 370 + 21.6 × lean mass, is the general prediction equation Cunningham published in 1991.⁵ This makes it a useful choice for people who know their body fat percentage, especially athletes or very lean individuals.

Choosing the Right Diet Profile

The way you split your calories among protein, carbs, and fat depends on your goals and preferences. A balanced diet (30/40/30) works well for most people who want steady energy and overall health. A high protein split is popular for people who are building muscle or trying to keep muscle while losing fat. A low carb approach can help people who feel better eating fewer starches and sugars. A keto diet is very high in fat and very low in carbs, which pushes the body to burn fat for fuel instead of glucose. A low fat split keeps fat intake minimal, which some people prefer for heart health.

There is no single "best" split for everyone. The right choice depends on your body, your activity level, your health conditions, and what you can stick with long-term.

Why Tracking Macros Matters

Counting calories alone tells you how much you're eating, but tracking macros tells you what you're eating. Two people can eat the same number of calories, but if one person eats mostly protein and vegetables while the other eats mostly sugar and oil, their results will be very different. Tracking macros helps you make sure you're getting enough protein to support your muscles, enough carbs to fuel your activity, and enough fat to keep your hormones and body working well. Pairing macro tracking with body composition metrics, such as your Waist to Hip Ratio, gives you a more complete picture of your progress.

Tips for Using Your Results

The numbers from this calculator are a starting point, not a perfect prescription. Every person's body is a little different. Use these targets for two to three weeks, track how you feel and whether your weight is moving in the direction you want, and then make small adjustments. If you're not losing weight, try reducing your daily intake by 100–200 calories. If you're feeling tired or your workouts are suffering, you may need more carbs or more total calories. For personalized medical or dietary advice, always consult a registered dietitian or your doctor.

Formulas used

Mifflin-St Jeor (Male) ¹

\text{BMR} = 10w + 6.25h - 5a + 5

Mifflin-St Jeor (Female) ¹

\text{BMR} = 10w + 6.25h - 5a - 161

Harris-Benedict (Male) ⁴

\text{BMR} = 88.362 + 13.397w + 4.799h - 5.677a

Harris-Benedict (Female) ⁴

\text{BMR} = 447.593 + 9.247w + 3.098h - 4.330a

Katch-McArdle (Cunningham 1991)

\text{BMR} = 370 + 21.6 \times \text{LBM}

TDEE & Target Calories

\text{Target} = \text{BMR} \times \text{Activity Factor} + \text{Goal Adjustment}

Macronutrient Grams

\text{Protein (g)} = \frac{\text{Target} \times P\%}{400}, \quad \text{Carbs (g)} = \frac{\text{Target} \times C\%}{400}, \quad \text{Fat (g)} = \frac{\text{Target} \times F\%}{900}

Frequently asked questions

What are macros in food?

Macros is short for macronutrients. They are the three main nutrients your body needs in large amounts: protein, carbohydrates, and fat. Every food you eat contains some mix of these three. Protein and carbs each have 4 calories per gram, while fat has 9 calories per gram.⁷

How many calories should I eat to lose weight?

This calculator finds your Total Daily Energy Expenditure (TDEE) and then subtracts calories based on your goal. For steady weight loss, it subtracts 500 calories per day; federal obesity guidance puts a deficit of 500 to 1,000 calories per day at a loss of 1 to 2 pounds per week.⁸ For slower weight loss, it subtracts 250 calories per day. The calculator will never set your target below 1,200 calories per day for safety.

What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep you alive. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. TDEE includes all the calories you burn from exercise, walking, and daily movement on top of your BMR.

Which BMR formula should I use?

For most people, Mifflin-St Jeor is the best choice. A systematic review found it the most reliable of the common equations.⁶ Use Katch-McArdle only if you know your body fat percentage, especially if you are lean or athletic. Harris-Benedict is the classic formula; in the Mifflin-St Jeor study its original equations overestimated measured resting energy expenditure by 5%.¹

How much protein do I need per day?

It depends on your goals and diet profile. On a balanced diet, about 30% of your calories come from protein. For a 2,000 calorie diet, that is about 150 grams of protein per day. If you are building muscle or trying to keep muscle while losing fat, a high protein split (40%) may be better. The calculator shows your exact protein target in grams based on your inputs.

What diet profile is best for building muscle?

The High Protein profile (40% protein, 35% carbs, 25% fat) is a good choice for building muscle. It gives you plenty of protein to repair and grow muscle tissue, plus enough carbs to fuel your workouts. Pair this with a Slow Gain or Gain Weight goal to make sure you are eating enough calories to support muscle growth.

What is the keto diet profile?

The keto profile sets your macros to 25% protein, 5% carbs, and 70% fat. This very low carb, high fat split pushes your body into a state called ketosis, where it burns fat for fuel instead of glucose. Keto can help with weight loss, but it is a strict diet that may not suit everyone.

How do I pick my activity level?

Choose the level that matches your typical week. If you sit at a desk most of the day and do not exercise, pick Sedentary. If you exercise 3 to 5 days a week at moderate effort, pick Moderately Active. If you do hard workouts 6 to 7 days a week or have a physically demanding job, pick Very Active. Be honest. Picking a higher level than your real activity will give you too many calories.

Do I need to know my body fat percentage?

No, not for most calculations. Body fat percentage is only needed if you choose the Katch-McArdle formula under Settings. The default Mifflin-St Jeor formula does not require it. However, if you do know your body fat percentage, Katch-McArdle can give a more accurate result, especially for lean or athletic people.

How often should I recalculate my macros?

Recalculate your macros every 4 to 6 weeks, or whenever your weight, activity level, or goals change significantly. As you lose or gain weight, your calorie needs change too. Regular recalculation keeps your targets accurate and helps you keep making progress.

What is the unit converter used for?

The unit converter appears when you select Other as your unit system. It lets you convert between units like stone, meters, inches, kilograms, and pounds. After converting, you can click Apply to Calculator to send the converted values directly into the height and weight fields.

What happens if I eat more fat and less carbs?

Shifting more calories to fat and fewer to carbs can help some people feel fuller and have more stable energy levels. This is the idea behind low carb and keto diets. However, because fat has 9 calories per gram compared to 4 for carbs, you will eat fewer total grams of food.⁷ The best split depends on how your body responds and what you can stick with.

Should I eat the same macros on rest days?

For most people, keeping the same macros every day is the simplest approach and works well. Some advanced athletes cycle their carbs, eating more on training days and less on rest days. If you are just starting out, stick with the same daily targets for consistency.

Sources

Rate this calculator