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.
-
Medtronic Is Notifying 3.8 Million People of a Data Breach — Here's What It Means for Patients
Medtronic, the world's largest medical device maker, is notifying 3,834,294 people that a data breach of its corporate IT systems in April 2...
-
The FDA Is Reviewing 7 Peptides on 23–24 July — Here's What That Does and Doesn't Mean
The FDA's Pharmacy Compounding Advisory Committee will review seven peptides — BPC-157, KPV, TB-500, MOTS-c, Emideltide (DSIP), Semax and Ep...
-
Researchers Push Back on the FDA's 2026 Wellness-Device Guidance — What It Means for Wearable Owners
A Nature Biomedical Engineering Comment published on 23 June 2026 argues that the FDA's 2026 General Wellness guidance leaves important ques...