Macro Calculator

Find your daily protein, carbohydrate and fat targets in grams from your body metrics, activity level and goal, using the Mifflin-St Jeor formula and weight-based scaling.

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Estimate daily calories and macronutrients

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Calculation Examples

Calculation Case Result
Cut: male, 30 years, 85 kg, 180 cm, moderately active (×1.55) BMR 1,830 → TDEE 2,837 → target 2,269 kcal: 204 g protein, 77 g fat, 191 g carbs
Maintain: female, 25 years, 60 kg, 165 cm, lightly active (×1.375) BMR 1,345 → TDEE and target 1,850 kcal: 108 g protein, 54 g fat, 233 g carbs
Bulk: male, 22 years, 70 kg, 175 cm, very active (×1.725) BMR 1,689 → TDEE 2,913 → target 3,204 kcal: 140 g protein, 63 g fat, 519 g carbs
Mihail Doncenco
Mihail Doncenco Site Creator & Calculator Expert

Founder and developer of CalcMate. Builds and maintains every calculator on this site, focusing on formula accuracy and clear, practical results.

How to Use the Macro Calculator

Enter your gender, age, height, current weight and activity level, then pick a goal: Cut (fat loss), Maintain or Bulk (muscle gain). Click Calculate to see your daily calories and gram targets for protein, fat and carbohydrates.

The calculator works in three stages. First, it computes your basal metabolic rate (BMR) with the Mifflin-St Jeor equation. Second, it multiplies BMR by your activity factor to get your total daily energy expenditure (TDEE). Third, it applies a goal modifier: a 20% calorie deficit for a cut, a 10% surplus for a bulk and no change for maintenance, with a floor of 1,200 kcal/day.

Instead of fixed percentage splits such as "30% protein", the tool scales nutrients to your body weight: 2.4 g of protein per kg for a cut, 2.0 g/kg for a bulk, 1.8 g/kg for maintenance and 0.9 g of fat per kg for every goal. Carbohydrates fill the remaining calories (protein and carbohydrate give 4 kcal per gram, fat 9 kcal per gram). Example, a cut for a 30-year-old man who is 180 cm and 85 kg with moderate activity (×1.55): BMR 1,830 kcal/day, TDEE about 2,837, target about 2,269 kcal/day, with 204 g protein, 77 g fat and 191 g carbohydrates.

How Your Macros Are Calculated

The Mifflin-St Jeor equation is the base of this calculator. A systematic review in the Journal of the American Dietetic Association (Frankenfield et al., 2005) found it within 10% of measured resting rate in more nonobese and obese adults than the Harris-Benedict, Owen or WHO/FAO/UNU equations: \[ \text{BMR}_{\text{men}} = 10W + 6.25H - 5A + 5 \] \[ \text{BMR}_{\text{women}} = 10W + 6.25H - 5A - 161 \] Here \(W\) is weight in kg, \(H\) is height in cm and \(A\) is age in years. TDEE equals BMR times an activity factor from 1.2 (sedentary) to 1.9 (super active). Protein and fat are then set per kg of body weight.

The protein targets follow the research. The ISSN position stand (2017) recommends 1.4 to 2.0 g/kg/day for people who train. A meta-analysis by Morton et al. (Br J Sports Med, 2018) found muscle gains from resistance training levelled off around 1.62 g/kg/day, with an upper confidence limit of 2.20 g/kg/day. The 2.4 g/kg used for a cut is higher on purpose: Helms et al. (Int J Sport Nutr Exerc Metab, 2014) suggested 2.3 to 3.1 g per kg of fat-free mass for lean, resistance-trained athletes in a deficit. That range applies to lean mass, so for people with a lot of body fat, 2.4 g per kg of total weight is generous.

Fat is set at 0.9 g/kg to keep essential fatty acids and the fat-soluble vitamins A, D, E and K covered. In the examples on this page it gives about 30% of calories in the cut, 26% at maintenance and 18% in the bulk, while the ACSM, Academy of Nutrition and Dietetics and Dietitians of Canada joint position (2016) recommends 20 to 35% of energy from fat for most athletes.

Macronutrient breakdown diagram showing protein, fat and carbohydrate gram targets for cut, maintain and bulk goals

Useful Tips 💡

  • Recalculate when your weight changes by 3 to 5 kg. Each kilogram changes BMR by 10 kcal/day, so losing 5 kg lowers TDEE by about 60 to 95 kcal/day, and the same calories will slowly stop producing fat loss.
  • Hit your protein target first each day, then worry about fat and carbohydrate precision. Protein is the macro with the strongest evidence for protecting muscle in a deficit and building it in a surplus.
  • Choose your activity level from your total weekly movement, not just gym sessions. Someone who trains 4 days a week but sits at a desk otherwise is usually lightly active, not very active.

📋Steps to Calculate

  1. Enter your gender, age, height and weight. Use kg and cm, or switch to lb and inches.

  2. Select your activity level based on your weekly exercise frequency, not your job activity alone.

  3. Choose your goal: Cut, Maintain or Bulk.

  4. Click Calculate to see daily targets for calories, protein, fat and carbohydrates.

Mistakes to Avoid ⚠️

  1. Selecting "Very Active" or "Super Active" when daily life is sedentary. Each step up the scale adds about 230 to 310 kcal/day at a BMR of 1,320 to 1,780 kcal/day, which can turn a deficit target into maintenance.
  2. Cutting below the 1,200 kcal/day floor on your own. Very low intakes risk nutrient gaps and muscle loss, and the 2013 AHA/ACC/TOS guideline lists 1,200 to 1,500 kcal/day for women and 1,500 to 1,800 kcal/day for men as typical calorie-restricted diets.
  3. Mixing unit systems, such as weight in pounds with height in centimeters. This produces a wrong BMR, so confirm both inputs use the same system before you calculate.
  4. Tracking only calories. Two 2,000 kcal days can differ a lot: 60 g of protein supplies 240 kcal of that, while 150 g supplies 600 kcal, and the body composition outcome over weeks is not the same.

Applications of Macro Tracking📊

  1. Fat loss (cut): Use the protein target (2.4 g/kg) to protect muscle in a deficit. An 85 kg person gets 204 g of protein a day, which is 816 kcal or about 36% of a 2,269 kcal target.

  2. Muscle gain (bulk): Find the surplus and carbohydrate target that fuel hard training. A 70 kg man gets a 10% surplus, 140 g of protein at 2.0 g/kg and about 519 g of carbohydrates (7.4 g/kg) on a 3,204 kcal day.

  3. Maintenance and general health: Set a stable intake that matches expenditure. A 60 kg woman who is lightly active lands at about 1,850 kcal with 108 g protein, 54 g fat and 233 g carbohydrates.

  4. Diet planning: Use the gram targets as daily goals when logging food in apps like MyFitnessPal or Cronometer, so your plan has measurable structure.

Questions and Answers

Can I use this as a keto macro calculator?

Yes, with a manual adjustment: keep the calorie and protein targets, cap carbohydrates at 20 to 50 g/day and move the freed calories into fat. For the 85 kg cut example (2,269 kcal, 204 g protein), 30 g of carbohydrates leaves about 148 g of fat. Fat has 9 kcal per gram, so each 100 g of carbohydrates you drop frees roughly 44 g of fat. Ketogenic diets can interact with medical conditions and medication, so check with a doctor first.

How is the macro calculator for weight loss different from a basic calorie counter?

A macro calculator for weight loss sets protein as well as calories, to protect muscle during the deficit. In a deficit the body can break down muscle for energy, which lowers lean mass and makes fat loss harder to keep. This tool assigns 2.4 g of protein per kg of body weight on a cut, so an 85 kg person gets 204 g a day. That is above the ISSN range for people who train (1.4 to 2.0 g/kg/day) and inside the 2.3 to 3.1 g per kg of fat-free mass that Helms et al. (2014) suggested for lean, resistance-trained athletes in a deficit. If you carry a lot of body fat, the same figure per kg of total weight is generous.

How often should I recalculate my macros?

Recalculate when your weight changes by about 3 to 5 kg. Each kilogram changes Mifflin-St Jeor BMR by 10 kcal/day, so losing 5 kg lowers BMR by 50 kcal/day and TDEE by about 60 to 95 kcal/day, depending on your activity factor. Protein and fat targets also scale with body weight and move at the same time. If you do not recalculate, the deficit shrinks and fat loss slows or stalls.

What is a macro calculator and how does it work?

A macro calculator turns your daily calorie target into gram targets for protein, carbohydrates and fat, based on your body metrics, activity level and goal. It estimates your total daily energy expenditure (TDEE) with the Mifflin-St Jeor equation and an activity multiplier, applies a goal adjustment, then sets protein and fat per kg of body weight and fills the remaining calories with carbohydrates. The result is a specific daily plan, such as 204 g protein, 77 g fat and 191 g carbohydrates, instead of one calorie number.

What makes this macro calculator more accurate than fixed-percentage tools?

Fixed percentages tie protein to total calories, while weight-based targets tie it to your body. At 1,200 kcal, 30% protein is only 90 g, which is 1.2 g/kg for a 75 kg person and below the 1.4 to 2.0 g/kg range for people who train. At 4,000 kcal, 30% protein is 300 g, or 4.0 g/kg, far more than the research supports. Weight-based scaling keeps protein and fat in a sensible range at any calorie level.

Why does the macro calculator for muscle gain allocate so many calories to carbohydrates?

Carbohydrates take the largest share in a bulk because protein and fat are fixed per kg of body weight, so carbohydrates fill everything left over. For a 70 kg man on 3,204 kcal, protein (140 g) and fat (63 g) use about 1,127 kcal, and the remaining 2,077 kcal, or 519 g, goes to carbohydrates. That is 7.4 g/kg, within the 6 to 10 g/kg/day that the ACSM, Academy of Nutrition and Dietetics and Dietitians of Canada position (2016) gives for 1 to 3 hours of daily training. Carbohydrates fuel hard training and refill muscle glycogen between sessions.

Why does the macro calculator use different values for men and women?

The Mifflin-St Jeor equation uses +5 for men and -161 for women, a difference of 166 kcal/day at the same age, weight and height. On average, women have less lean mass at the same body weight, and lean mass burns more energy at rest than fat. Using the male constant for a 25-year-old woman who weighs 60 kg and is 165 cm tall would give a BMR of about 1,511 kcal/day instead of 1,345, which overstates her needs and can turn a planned deficit into maintenance.
Disclaimer: This calculator is designed to provide helpful estimates for informational purposes. While we strive for accuracy, financial (or medical) results can vary based on local laws and individual circumstances. We recommend consulting with a professional advisor for critical decisions.