What are macronutrients?

Macronutrients are nutrients your body needs in large amounts: protein (4 kcal/g), carbohydrates (4 kcal/g), and fat (9 kcal/g). They provide energy and serve structural/functional roles — protein builds tissue, carbs fuel activity, fat supports hormones and cell membranes.

What is a good macro split for weight loss?

A high-protein split like 30–35% protein, 35–40% carbs, 25–30% fat works well for most people cutting. Higher protein preserves muscle during a deficit. The specific ratio matters less than total calories and adequate protein intake.

What is a good macro split for muscle gain?

For bulking, try 25–30% protein, 45–50% carbs, 20–25% fat. More carbs fuel intense training and support muscle glycogen. Protein needs don't increase dramatically in a surplus — 1.6–2.0 g/kg is sufficient when calories are abundant.

How much protein do I need per day?

General health: 0.8 g/kg (RDA minimum). Active individuals: 1.2–1.6 g/kg. Muscle building: 1.6–2.2 g/kg. Cutting while preserving muscle: 2.0–2.4 g/kg. These ranges are supported by meta-analyses of protein intake and lean mass outcomes.

What is IIFYM (If It Fits Your Macros)?

IIFYM is a flexible dieting approach where any food is acceptable as long as it fits your daily macro targets. It allows dietary freedom while maintaining structure. Critics note it doesn't account for micronutrients or food quality, so balance flexibility with whole food intake.

Should I track net carbs or total carbs?

For general macro tracking, use total carbs. Net carbs (total minus fiber) are primarily used in ketogenic diets. The difference only matters if you're specifically limiting carbs for ketosis. For standard macro tracking, total carbs are the convention.

Do I need to hit my macros exactly?

No. Aiming within ±5–10g of each target is sufficient. Protein is the most important to hit consistently; carbs and fat can flex more. Perfect adherence isn't required — consistency over time matters more than daily precision.

How do I adjust macros if I'm not losing weight?

First, verify you're tracking accurately (use a food scale, include everything). If tracking is solid, reduce calories by 10% — typically from carbs and/or fat while maintaining protein. Use our [Calorie Calculator](/tools/calorie-calculator) to recalculate your targets. Give each adjustment 2–3 weeks before reassessing.

Can I build muscle in a calorie deficit?

Yes, especially if you're new to lifting, returning after a break, or have significant fat to lose. This is called body recomposition. High protein (2.0+ g/kg) and resistance training are essential. Progress is slower than in a surplus but achievable.

What is the thermic effect of food (TEF)?

TEF is the energy used to digest, absorb, and process nutrients. Protein has the highest TEF (~20–30%), carbs are moderate (~5–10%), fat is lowest (~0–3%). High-protein diets slightly increase total calorie burn through TEF.

How do I calculate macros for keto?

Keto typically requires <20–50g carbs/day, moderate protein (1.2–1.7 g/kg), and high fat (60–75% of calories). This calculator uses a balanced split; for keto, you'd need to manually adjust or use a keto-specific calculator.

Should I eat before or after workouts?

Both help. Pre-workout carbs and protein (1–3 hours before) fuel performance. Post-workout protein (within a few hours) supports muscle protein synthesis. The 'anabolic window' is wider than once thought — total daily intake matters more than exact timing.

How do macros differ for men vs women?

Calorie needs differ (men typically need more), but macro percentages are similar. Women may benefit from slightly higher fat intake (25–35%) for hormonal health, especially if experiencing menstrual irregularities on very low-fat diets.

What's the minimum fat intake I should have?

Don't go below 0.5 g/kg body weight or 15–20% of total calories. Fat is essential for hormone production, brain function, and absorption of vitamins A, D, E, K. Very low-fat diets can impair testosterone, estrogen, and overall health.

How do I track alcohol in my macros?

Alcohol has 7 kcal/g and is metabolized differently than macros. Most trackers count it separately. Pragmatically, you can 'borrow' from carbs or fat to account for alcohol calories, but it provides no nutritional benefit and can impair muscle protein synthesis.

Online Medical Tools — Macro Calculator

Printed on 8/14/2026

For informational purposes only. This is not medical advice.

Nutrition

Macro Calculator

Macronutrients — protein, carbohydrates, and fat — are the building blocks of your diet. This calculator converts your calorie target into actionable gram targets for each macro, using evidence-based splits optimized for your fitness goal: weight loss (cutting), maintenance, or muscle gain (bulking).

Formula: Protein: 30% of calories ÷ 4, Carbs: 40% ÷ 4, Fat: 30% ÷ 9

Sex

Age

years

Height

Weight

Activity Level

Goal

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How It Works

Calculate your TDEE

Enter your stats and activity level. The calculator first determines your Total Daily Energy Expenditure using the Mifflin-St Jeor equation, then adjusts for your goal. Already know your TDEE? Use our [TDEE Calculator](/tools/tdee-calculator) to calculate it separately.

Apply your macro split

Your calorie target is divided into protein (30%), carbohydrates (40%), and fat (30%). This balanced split works for most goals; athletes may customize further.

Get your daily gram targets

View your protein, carb, and fat targets in grams per day. Use these numbers to plan meals, track intake, or set up your food tracking app.

Who Uses the Macro Calculator

Body Recomposition

Lifters seeking fat loss + muscle

Macro tracking ensures adequate protein (1.6–2.2 g/kg) during a deficit, preserving muscle while losing fat. This is the foundation of successful recomposition.

Contest Prep

Bodybuilders & physique athletes

Precision macro tracking is essential for competition prep. Competitors adjust macros weekly based on progress photos, weight trends, and performance.

Endurance Performance

Runners, cyclists & triathletes

Endurance athletes need higher carbohydrate ratios (50–60%) to fuel training. Macro calculators help ensure adequate glycogen replenishment.

IIFYM / Flexible Dieting

Anyone seeking dietary flexibility

If It Fits Your Macros (IIFYM) allows food flexibility while hitting targets. Knowing your macros lets you enjoy varied foods without derailing progress.

Lean Bulk

Natural lifters gaining muscle

A controlled surplus with adequate protein maximizes muscle gain while minimizing fat accumulation. Macro targets prevent 'dirty bulking' excess.

Nutrition Coaching

Dietitians & coaches

Coaches use macro calculators to set initial client targets, then adjust based on adherence, progress, and feedback over weeks of tracking.

Pro Tips

Prioritize protein first

Hit your protein target every day — it's the most important macro for body composition. Carbs and fat can flex more; protein should be consistent.

Protein: 1.6–2.2 g/kg for muscle goals

Research consistently shows this range optimizes muscle protein synthesis. Higher isn't necessarily better — 2.2 g/kg is the practical ceiling for most people.

Increase protein when cutting

During a deficit, bump protein to 2.0–2.4 g/kg to preserve muscle. The leaner you get, the more protein matters for preventing muscle loss.

Time carbs around training

Eating carbs before and after workouts improves performance and recovery. If carbs are limited, prioritize them in your pre/post-workout meals.

Don't fear dietary fat

Fat is essential for hormone production (including testosterone), brain function, and vitamin absorption. Don't drop below 0.5 g/kg or 20% of calories.

Use a food scale for accuracy

Eyeballing portions typically underestimates intake by 20–50%. A $15 food scale is the single best investment for accurate macro tracking.

Track consistently for 2 weeks minimum

Don't adjust macros based on one day or one weigh-in. Track consistently for 2+ weeks, then assess trends before making changes.

Allow 10% flexibility

Hitting macros within ±5–10g is perfectly fine. Obsessing over exact numbers creates stress without meaningful benefit. Consistency beats perfection.

Adjust macros as weight changes

Losing 5 kg? Your [TDEE](/tools/tdee-calculator) dropped ~200 kcal. Recalculate every 4–8 weeks to ensure your macros still match your current body and goals.

Focus on food quality too

Macros matter, but so do micronutrients. Hitting your macros from whole foods (lean meats, vegetables, whole grains) beats processed alternatives for health.

Common Questions About Your Results

Evidence-Based Methodology

Protein recommendations (1.6–2.2 g/kg for muscle building) are based on meta-analyses published in the British Journal of Sports Medicine (Morton et al., 2018). The default macro split aligns with position statements from the International Society of Sports Nutrition (ISSN) and Academy of Nutrition and Dietetics.

Clinical Content Trust

Last reviewed:: April 21, 2026
Guideline version:: General evidence framework v2026.04
Source set version:: Primary-source set v1

How to Interpret Your Result

Your results show daily gram targets for protein, carbohydrates, and fat, along with the total calorie target adjusted for your goal (maintenance, weight loss, or muscle gain). Protein and carbohydrates each provide 4 calories per gram, while fat provides 9 calories per gram.

The protein target (30% of calories) generally falls within the 1.6–2.2 g/kg range recommended for active individuals. The carbohydrate target (40%) provides the primary fuel for exercise and brain function. The fat target (30%) supports hormone production, cell membrane integrity, and absorption of fat-soluble vitamins (A, D, E, K). These are starting targets — adjust them based on your individual response, training demands, and preferences.

When to Use This Tool

Use this calculator after determining your TDEE to break your calorie target into actionable macronutrient goals. It is especially useful when starting a structured nutrition plan for body recomposition, athletic performance, or weight management.

Macro tracking is particularly valuable during a calorie deficit (cutting), where adequate protein intake is critical to preserve lean muscle mass. It is also helpful for athletes who need to ensure sufficient carbohydrate intake to fuel training and recovery.

Limitations

The default 30/40/30 split (protein/carbs/fat) is a general-purpose starting point and may not be optimal for everyone. Endurance athletes often benefit from a higher carbohydrate ratio (50–60%), while individuals on ketogenic or low-carb diets will need a fundamentally different macro distribution.

This calculator does not account for micronutrient needs, meal timing, or food quality — all of which matter for health and performance beyond macros alone. Individuals with kidney disease should consult a clinician before adopting a high-protein diet, as excessive protein intake may accelerate renal decline in those with pre-existing kidney conditions.

As with TDEE, the underlying calorie estimate is approximate. Use your macro targets as a starting framework and adjust based on real-world results over 2–3 weeks.

Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.

Changelog

April 21, 2026 · trust-baseline
Clinical trust metadata enabled for this tool page with structured review/version fields.

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