Macro Calculator (Protein, Carbs, Fat)
Macro nutrient calculator. Protein, carbs, fat targets from TDEE + body weight + goal (cut, maintain, bulk). Evidence-based ratios per ISSN + Helms 2014.
Macro Calculator
How to use the macro calculator
Enter weight + TDEE
Body weight in kg (use the RMR calculator first to get your TDEE if you don't know it). TDEE = Total Daily Energy Expenditure ≈ RMR × activity multiplier. Both numbers anchor the macro calculation.
Choose goal
Maintain: TDEE calories. Cut mild (-300): ~0.3 kg/week loss. Cut aggressive (-500): ~0.5 kg/week loss. Bulk mild (+250): ~0.2 kg/week gain. Bulk aggressive (+500): ~0.5 kg/week gain. Aggressive bulks risk excess fat gain; aggressive cuts risk muscle loss + mood/performance issues.
Set protein per kg
1.6-2.2 g/kg/day is the ISSN-position evidence-based range for muscle preservation + growth. Higher end (2.0-2.2) during cuts or for trained lifters. Lower end (1.6-1.8) for sedentary or moderate goals. Above 2.5 is rarely additionally beneficial; below 1.4 risks muscle loss especially during deficit.
Set fat percentage
20-30% of calories from fat is typical. Minimum: ~0.5 g/kg body weight (essential fatty acids + hormone production). Some athletes prefer higher fat (35-40%) for keto/satiety; others prefer lower (20%) to leave more room for carbs. Within reasonable ranges, body composition outcomes are similar.
Carbs fill the remaining calories
Carbs aren't "essential" macronutrient-wise (the body can survive without dietary carbs) but they're the cheapest energy source + critical for high-intensity training. Carb intake = (total calories − protein kcal − fat kcal) / 4. For most active individuals, 3-5 g/kg/day carbs supports training; less for sedentary, more for endurance athletes.
Macros — protein matters most, then total calories, then ratio
Macronutrient targeting ("macros") emerged from the bodybuilding + flexible dieting community and became mainstream through IIFYM (If It Fits Your Macros) culture. Three numbers: protein grams, carb grams, fat grams. Total calories = 4×protein + 4×carbs + 9×fat. The science of macros consolidated in the 2010s — the International Society of Sports Nutrition (ISSN) position stand established protein at 1.6-2.2 g/kg/day for active individuals, with fat 20-30% of calories and carbs filling the remainder. Eric Helms\' 2014 evidence-based bodybuilding paper (J Int Soc Sports Nutr) brought academic rigor to what had been gym-bro lore. Today every fitness app + nutritionist uses some version of macro targeting.
Hierarchy of nutritional importance
Modern evidence-based nutrition prioritises: (1) Total calories — calories in vs out is the primary driver of weight change. (2) Protein — sufficient protein preserves muscle during cuts + supports growth during bulks. (3) Fat + carb ratio — within reasonable bounds, this matters less than calories + protein. Keto vs high-carb vs moderate produces similar body composition outcomes when calories + protein are matched. (4) Meal timing — minimal impact on body composition for most people; matters more for high-level athletes. (5) Micronutrients — important for health but rarely body-composition-relevant at moderate variation.
Diet wars (keto vs paleo vs Mediterranean vs IIFYM) are mostly noise. Match calories + protein, and the choice between 50% carbs vs 30% carbs is less consequential than internet debates suggest.
Protein per kg — why higher in deficits
During caloric surplus (bulk), 1.6 g/kg/day protein is enough for muscle protein synthesis. During caloric deficit (cut), protein needs rise: muscle protein breakdown is elevated; preserving muscle while losing fat requires MORE protein. Studies in lean trained subjects (Helms 2014, Phillips 2016) show 2.0-2.4 g/kg/day during aggressive cuts. For sedentary individuals: ~0.8-1.2 g/kg suffices. For athletes/lifters during normal training: 1.6-2.0. For athletes during cuts: 2.0-2.4. The calculator default of 2.0 g/kg works for most lifters; reduce to 1.6 if sedentary or increase to 2.4 if very lean + cutting aggressively.
ASEAN food culture vs macro targeting
Macro tracking can clash with ASEAN traditional cuisines. Rice-heavy bases (Chinese, Malay, Indonesian, Thai) often push carb intake higher than typical Western macro plans. Fish + tofu + chicken provide adequate protein. Coconut oil + palm oil push fat higher. Adapt the ratios to your culture: many South + East Asian athletes thrive on 55-65% carbs, 15-25% protein, 15-25% fat — different from Western "balanced" 40/30/30. The science doesn\'t mandate Western ratios; cultural-traditional patterns work fine if total calories + protein are sufficient.
10 Things to Know About Macros
1g protein = 4 kcal, 1g carb = 4 kcal, 1g fat = 9 kcal. Memorise these.
ISSN position: 1.6-2.2 g/kg/day protein for active individuals.
Total calories > macro split for body composition outcomes (assuming adequate protein).
Helms 2014: 2.0-2.4 g/kg/day protein during aggressive cuts to preserve muscle.
Fat minimum: ~0.5 g/kg/day for essential fatty acids + hormone production.
Carbs are NOT essential nutritionally but support high-intensity training + brain glucose.
IIFYM (If It Fits Your Macros): track macros + total calories. Food source matters less for composition than people think.
Aggressive cuts: -500 kcal/day = ~0.5 kg/week loss. Faster = more muscle loss risk.
Lean bulks: +250 kcal/day. Aggressive bulks (+500) produce more fat gain.
Diet adherence > optimal macros. Pick ratios you can sustain for months, not a perfect plan you abandon in 2 weeks.
Frequently asked questions
1.6-2.2 g/kg/day per ISSN. Sedentary: 1.2-1.6. Active/lifter at maintenance: 1.6-2.0. Aggressive cut: 2.0-2.4. Very lean physique competitor: 2.4-2.8. Above 2.5 is rarely additionally beneficial. Below 1.4 risks muscle loss during cuts.
For body composition: equivalent when calories + protein matched. For specific contexts: keto can help insulin-sensitive individuals + people who feel better with stable blood sugar; high-carb supports high-intensity training better; Mediterranean fits cardiovascular health. Pick what you can sustain.
Both matter, in priority order: calories > protein > fat/carb ratio. At matched calories, hitting protein target preserves muscle mass + supports recovery. Fat vs carb ratio within 20-50% fat range produces similar body comp outcomes. So: hit calorie target + protein target consistently; the rest is variable.
MyFitnessPal, Cronometer, Lose It! — apps with food databases. Weigh food on a kitchen scale (more accurate than visual estimation, which typically underestimates by 20-40%). Track 7-14 days to establish baseline, then adjust.
No — weekly averaging is fine for most people. Going under protein one day + over the next is usually neutral. Total weekly calorie balance drives weight outcomes more than perfect daily macros. Some athletes use targeted refeeds (high-carb days) within a weekly deficit framework.
Less important than once believed. The "anabolic window" (post-workout protein) is several hours wide, not 30 minutes. Total daily protein + distribution across 3-5 meals matters more than precise timing. Intermittent fasting works if total calories + protein are met. Pick eating pattern you can sustain.
Standard "40/30/30" or "Zone diet" macros are just one option. ASEAN traditional diets often run 55-65% carbs / 15-25% protein / 15-25% fat — totally fine. Mediterranean runs higher fat (35-40%) from olive oil. Keto runs 70%+ fat. The science supports outcomes more than ratios — match calories + protein, find a ratio you sustain.
No. All inputs stay in your browser.
Track 2 weeks. If weight is stable on cut macros: TDEE was overestimated. Drop calories by 150-200 kcal/day (reduce carbs typically) + retest. If weight loss too fast: increase by 150-200 kcal/day. Be patient — water + glycogen fluctuations mask real trends in the first 1-2 weeks.
Eric Helms\' Muscle and Strength Pyramid (book + free PDFs). ISSN position stands at jissn.com. Lyle McDonald\'s books + website. Stronger By Science (Greg Nuckols).
Related News
You may be interested in these recent stories from our newsroom.
-
The FDA wants clinical trials to report in real time, with AI doing the watching
The US Food and Drug Administration has started two pilot trials that send their results to the agency as the data comes in, rather than in...
-
Bayesian Health Wins First FDA Clearance for Continuous AI Sepsis Monitor, Study Shows 18% Mortality Drop
Bayesian Health's TREWS system became the first AI device cleared by the FDA to continuously monitor all hospitalised patients for sepsis —...
-
Commure Raises US$70M at US$7B Valuation to Deploy AI Agents Across Hospital Administration
On 19 May 2026, Commure closed a US$70 million round at a US$7 billion post-money valuation, led by General Catalyst. Its AI agents already...
75 more free tools
Calculators, converters, security tools — no signup.