Macro Calculator
Get your daily calorie and macro targets — protein, carbs, and fat — for weight loss, maintenance, or building muscle. Based on your stats and goal.
Built and reviewed by Jesse · Last reviewed
Fill in your details to see your daily calories and macros.
- Enter your stats. Sex, age, height, weight, and activity level set your maintenance calories.
- Choose your goal. Fat loss, maintenance, or muscle gain adjusts calories up or down from maintenance.
- Read your calories and macros. Protein is anchored to body weight, fat to a share of calories, and carbs fill the rest.
How this macro calculator works
Your body burns a baseline number of calories just to stay alive — your Basal Metabolic Rate (BMR). Add the energy you burn moving and exercising and you get your Total Daily Energy Expenditure (TDEE), or maintenance calories. Eat below it to lose fat, above it to gain muscle. This tool does that math and splits the result into protein, carbs, and fat so you know not just how much to eat, but what to eat.
The exact split used
The calculator starts with Mifflin–St Jeor BMR and multiplies it by the activity level you select. It subtracts 500 kcal for fat loss, leaves maintenance unchanged, or adds 300 kcal for muscle gain. Protein is set at 1.8 g per kilogram of body weight. Fat receives 25% of total calories. Carbohydrate fills the calories left after protein and fat.
| Goal | Calorie adjustment | Purpose |
|---|---|---|
| Lose fat | TDEE − 500 kcal | Moderate starting deficit |
| Maintain | TDEE | Estimated stable intake |
| Build muscle | TDEE + 300 kcal | Modest starting surplus |
A worked macro example
For a 75 kg adult with a 2,400 kcal fat-loss target, protein is 135 g (75 × 1.8), which supplies 540 kcal. Fat is about 67 g because 25% of 2,400 is 600 kcal, and fat has 9 kcal per gram. The remaining 1,260 kcal becomes about 315 g of carbohydrate at 4 kcal per gram. Rounding means the displayed grams may differ from the calorie target by a few calories.
This is one evidence-informed split, not the only valid split. Protein is anchored because it supports muscle maintenance and growth. The division between fat and carbohydrate is more flexible. Someone who prefers higher-fat foods can raise fat and reduce carbohydrate by the same calories; an endurance athlete may prefer more carbohydrate to support training.
How to use the target in real life
Treat the result as a daily average. Hitting each gram exactly is not necessary: prioritize total calories and protein, then let carbohydrate and fat vary within a range that fits your food preferences. A practical first pass is to stay within about 5–10 g of protein and within roughly 100 kcal of the daily target.
Do not adjust the result after one unusual weigh-in. Weigh under similar conditions, compare seven-day averages, and give the plan two to three weeks. If the trend is flat during a fat-loss phase despite consistent tracking, decrease intake by 100–200 kcal. If weight is changing too quickly, hunger is extreme, or training performance drops, add calories back. See our guide to calibrating a TDEE estimate for the full process.
Important limitations
The largest uncertainty is usually the activity multiplier, not the arithmetic. Two people with the same age, height, and weight can have different energy needs because of body composition, step count, occupation, training volume, and genetics. Food labels and portion tracking also contain error. The useful number is the intake that produces the intended trend over time, not the most precise-looking result on day one.
This calculator is for healthy adults. It is not designed for pregnancy, breastfeeding, people under 18, clinical diets, or anyone with an eating disorder or a condition affecting nutrition or metabolism. A registered dietitian or physician can account for needs an automated formula cannot.
Macro split
calories = TDEE +/- goal adjustment
protein(g) = 1.8 x weight(kg)
fat(g) = (calories x 0.25) / 9
carbs(g) = (calories - protein x 4 - fat x 9) / 4- 4
- = calories per gram of protein and of carbohydrate
- 9
- = calories per gram of fat
- 0.25
- = share of total calories assigned to fat
Maintenance calories (TDEE) use the Mifflin-St Jeor BMR times an activity factor.
What are macros?
Macros (macronutrients) are protein, carbohydrates, and fat — the three nutrients that provide calories. Hitting the right split helps you lose fat, maintain, or build muscle while eating enough of each.
How are my macros calculated?
We estimate your maintenance calories (TDEE) from your stats and activity level, adjust for your goal, then set protein based on your body weight, fat at about 25% of calories, and the rest as carbohydrates.
What macros should I eat for weight loss?
This calculator sets a 500 kcal daily deficit from your estimated maintenance calories — a target associated with roughly 0.5 kg of fat loss per week. Protein is kept at 1.8 g per kg of body weight to help preserve muscle during the deficit. Fat is set at 25% of your target calories, with carbohydrate filling the remainder. The most important variable is the total calorie target; the protein floor is the second priority. The split between fat and carbohydrate can be adjusted to your food preferences without changing your rate of fat loss, as long as calories and protein stay on target.
What macros should I eat to build muscle?
The calculator adds 300 kcal above your estimated maintenance — a modest surplus aimed at supporting muscle growth while limiting excess fat gain. Protein remains at 1.8 g per kg of body weight, which is within the range most exercise science research supports for muscle protein synthesis. If you are new to resistance training, you may gain muscle even in a small deficit or at maintenance; a surplus becomes more important once you are past the early adaptation phase.
Are macros different for men and women?
The formula is the same — TDEE is estimated from height, weight, age, sex, and activity, then adjusted for your goal. Men typically have a higher TDEE because they tend to have more lean mass, so their absolute calorie and macro numbers come out higher. The protein target (1.8 g/kg) and the fat percentage (25% of calories) apply equally regardless of sex.
What are cutting macros?
Cutting is a training term for a fat-loss phase where the goal is to reduce body fat while preserving muscle. Select 'Lose fat' as your goal and the calculator gives you a cutting macro split: a moderate calorie deficit, high protein (1.8 g/kg), and fat and carbohydrate adjusted around that protein floor. Some people increase protein slightly beyond this during a cut to further protect muscle — up to 2.2 g/kg is well within evidence-supported ranges.
How much protein should I eat?
This calculator uses about 1.8 grams of protein per kilogram of body weight — a well-supported target for active people who want to preserve or build muscle. For a 75 kg person that is 135 g of protein per day. Evidence suggests that intakes between 1.6 and 2.2 g/kg cover the needs of most active adults; going above 2.2 g/kg produces diminishing returns for most people.
How do I use my macros in practice?
Prioritize total daily calories and protein first. Tracking every gram of fat and carbohydrate precisely is not necessary — staying within 5–10 g of your protein target and within roughly 100 kcal of your daily calorie target is close enough for most people. Weigh yourself weekly rather than daily, compare 7-day averages, and give the plan 2–3 weeks before adjusting. If fat loss stalls despite consistent tracking, reduce intake by 100–200 kcal. If energy or training performance drops sharply, add some calories back.
Is this medical advice?
No. These are estimates for healthy adults. If you have a medical condition or are pregnant, talk to a doctor or registered dietitian before changing your diet.
References
- Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247.
- Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20.
FitCalcs calculators provide general estimates for healthy adults and are not medical advice.
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