Macro Calculator
Find your exact macros in 30 seconds. A premium tool for evidence-based nutrition planning.
Your Details
Results update automatically as you type
Fill in your details
Results appear instantly as you type
More Free Calculators
The CalcMacros Macro Calculator is the most detailed free nutrition calculator available — no email required, no paywalls, and no guesswork. Whether you're trying to lose fat, build muscle, or understand exactly what you should be eating each day, this tool gives you a complete picture in seconds.
Enter your age, sex, height, weight, activity level, and goal. The calculator instantly outputs your Total Daily Energy Expenditure (TDEE), your adjusted calorie target, and a full macro breakdown — protein, carbs, and fat — in grams and calories. Results are displayed with animated charts that make your numbers easy to understand at a glance.
How to Use the Macro Calculator
Using CalcMacros takes less than 60 seconds. Here's how to get your numbers:
- Choose your unit system — Metric (kg/cm) or Imperial (lbs/ft). Your preference is saved automatically.
- Enter your age, sex, height, and weight — These inputs determine your Basal Metabolic Rate (BMR).
- Select your activity level — Be honest here. Most people are "lightly active" or "moderately active." Overestimating activity is the #1 cause of inaccurate TDEE calculations.
- Choose your goal — Lose fat, build muscle, maintain, or recompose. The calculator adjusts your calorie target accordingly.
- Select a diet type — Standard, High-Protein, Keto, Low-Carb, or High-Carb. This sets your macro ratios.
- Review your results — Your TDEE, target calories, and macro split appear instantly in the results panel.
Results update automatically as you change any input — no need to click a button. You can also copy your full results to clipboard with the "Share my results" button for easy tracking in notes or apps.
Understanding Your Results
TDEE (Total Daily Energy Expenditure)
Your TDEE is the total number of calories your body burns every day, factoring in your resting metabolism, digestion, and all physical activity. This is your maintenance calorie level — the amount you'd eat to neither gain nor lose weight. Want to learn more about your daily calorie burn? Visit our dedicated TDEE Calculator.
Target Calories
Your target calorie intake is your TDEE adjusted for your specific goal. For fat loss, the calculator applies a 10–20% calorie deficit. For muscle gain, it adds a 10–15% surplus. For maintenance and body recomposition, you eat at TDEE. A hard floor is applied — your target will never drop below BMR + 200 calories, which protects against dangerously low intake.
Protein, Carbs, and Fat
Your macros are calculated by applying your chosen diet type's ratio to your target calorie intake. Protein provides 4 calories per gram, carbohydrates provide 4 calories per gram, and fat provides 9 calories per gram. If your protein falls below the minimum recommended for muscle preservation (1.6g/kg of bodyweight), the protein floor is automatically applied and flagged with a notice.
The Donut Chart
The animated donut chart shows your macro split as a percentage of total calories — not by weight in grams. This is the correct way to visualize macros because fat has 2.25× more calories per gram than protein and carbohydrates. A "30% protein" diet means 30% of your calories come from protein, not 30% of the weight of your food.
How We Calculate Your Macros
CalcMacros uses the Mifflin-St Jeor equation by default — the formula with the highest validated accuracy for estimating BMR in the general population, according to multiple peer-reviewed studies including Frankenfield et al. (2005) in the Journal of the American Dietetic Association.
Mifflin-St Jeor (Default)
Developed in 1990, this formula accounts for weight, height, age, and sex. It consistently outperforms older formulas in accuracy tests across diverse populations.
Harris-Benedict (Revised 1984)
The original formula, revised by Roza and Shizgal in 1984. It tends to overestimate calorie needs by 50–100 calories compared to Mifflin-St Jeor, particularly for sedentary individuals. Still widely used in clinical settings.
Katch-McArdle
The most accurate formula for individuals who know their body fat percentage, as it calculates BMR based on lean body mass rather than total body weight. Particularly useful for very muscular or very lean individuals where the other formulas may be less accurate.
Activity Multipliers
Once your BMR is established, it's multiplied by an activity factor to produce your TDEE. The multipliers used (1.2 to 1.9) are from the original research by Harris and Benedict and are the standard in sports nutrition and dietetic practice.
Macro Ratios by Goal
The "right" macro ratio depends on your goal, diet preference, and training style. Here are the evidence-based ratios used by CalcMacros, based on guidelines from sports nutrition research:
| Goal / Diet | Protein | Carbs | Fat |
|---|---|---|---|
| Fat Loss | 40% | 35% | 25% |
| Body Recomposition | 35% | 40% | 25% |
| Maintenance | 30% | 40% | 30% |
| Muscle Gain | 30% | 45% | 25% |
| Keto | 25% | 5% | 70% |
| Endurance | 25% | 55% | 20% |
Note: These are percentage of total calories, not percentage of food weight. The protein floor rule ensures you always eat at least 1.6g of protein per kilogram of bodyweight, regardless of your diet type — this is the minimum proven to preserve muscle mass during a calorie deficit.
Frequently Asked Questions
A macro calculator estimates how many grams of protein, carbohydrates, and fat you should eat each day based on your body stats and fitness goal. It works by first calculating your Total Daily Energy Expenditure (TDEE) — how many calories you burn daily — and then splitting those calories into the three macronutrients according to your chosen diet type and goal.
TDEE stands for Total Daily Energy Expenditure. It is the total number of calories your body burns in 24 hours. Knowing your TDEE gives you a precise calorie target for your macro split: eat below it to lose fat, eat at it to maintain weight, and eat above it to build muscle. For a dedicated breakdown of your daily energy expenditure, try our <a href="/tdee-calculator">TDEE Calculator</a>.
The calculator uses the Mifflin-St Jeor equation, which peer-reviewed research identifies as the most accurate BMR formula for the general population, with a typical error margin of ±10%. However, no calculator can account for individual metabolic variation. Use the result as a starting point, track your weight for 2–3 weeks, and adjust your calories by ±100 per day based on results.
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — essentially the energy needed to keep your heart beating, lungs breathing, and brain functioning. TDEE adds all physical activity on top of BMR. For most people, BMR accounts for 60–70% of their TDEE. You should never eat below your BMR for extended periods.
To lose weight, aim to eat 10–20% below your TDEE in total calories. A typical macro split for fat loss is 40% protein, 35% carbohydrates, and 25% fat. Prioritizing protein (at least 0.7–1g per pound of bodyweight) preserves muscle tissue while your body burns fat for energy. A 500-calorie daily deficit typically produces approximately 1 lb of fat loss per week.
Both work equally well — the calculator converts between them internally. Use whichever unit you think in. If you know your weight in kilograms and height in centimeters, use metric. If you know your weight in pounds and height in feet and inches, use imperial. The mathematical results are identical either way.
Recalculate your macros every 4–6 weeks, or whenever your body weight changes by more than 5 lbs (2.3 kg), your activity level changes significantly, or your fitness goal shifts. As you lose or gain weight, your TDEE changes, so your calorie and macro targets must be updated to keep making progress.
Both formulas estimate BMR, but were developed at different times using different population samples. The Mifflin-St Jeor equation (1990) is generally considered more accurate for modern populations and is the default in this calculator. The Harris-Benedict equation (revised 1984) tends to produce slightly higher estimates, which can lead to overestimating calorie needs. For most users, the difference is 50–100 calories per day.
Macros (macronutrients) are the three main nutrients your body uses for energy: protein, carbohydrates, and fat. Protein provides 4 calories per gram and is essential for muscle repair and growth. Carbohydrates provide 4 calories per gram and are your body's primary fuel source. Fat provides 9 calories per gram and supports hormone production, brain function, and vitamin absorption. Tracking macros gives you precise control over body composition.
Yes — this is called body recomposition, and it is most achievable for beginners, people returning after a break, or those with a significant amount of body fat to lose. It requires eating at or very near your TDEE with very high protein intake (1g per pound of bodyweight), combined with consistent resistance training. Progress is slower than dedicated bulking or cutting phases, but body composition improves simultaneously.