Find your target protein, carbs, and fat (IIFYM) based on your weight goals and diet style.
Protein
197g
30% · 4 kcal/g
Carbs
263g
40% · 4 kcal/g
Fat
88g
30% · 9 kcal/g
Start with these targets and track your weight for two to three weeks. If progress stalls, adjust calories by 5–10%. Hitting your weekly average matters more than being exact every day.
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 before making any health-related decisions or starting any diet or exercise programme.
Tip: many lifters prefer to set protein at 1.6–2.2 g per kg of body weight (0.7–1 g per lb) and fill the rest with carbs and fat. The result card shows your protein in g/kg so you can check.
BMR (Mifflin-St Jeor) = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 (men) or − 161 (women)
TDEE = BMR × activity factor (1.2 – 1.9)
Calorie target = TDEE − 500 (lose), + 0 (maintain) or + 300 (gain), never below 1,500 (men) / 1,200 (women)
Protein g = calories × protein % ÷ 4 · Carbs g = calories × carb % ÷ 4 · Fat g = calories × fat % ÷ 9
First estimate your daily calorie needs: calculate BMR with the Mifflin-St Jeor equation, multiply by an activity factor to get TDEE, then subtract about 500 kcal to lose fat or add about 300 kcal to gain muscle. Next, split those calories by percentage into protein, carbs and fat, and convert to grams: protein and carbs have 4 kcal per gram, fat has 9 kcal per gram.
Total calories matter most for weight loss, so the best ratio is one you can stick to. Higher protein (around 30–40% of calories, or 1.6–2.2 g per kg of body weight) helps preserve muscle and keeps you fuller in a deficit. Carbs and fat can then be split according to preference and training needs.
The minimum for sedentary adults is 0.8 g per kg of body weight. People who strength train or are dieting usually benefit from 1.6–2.2 g per kg (about 0.7–1 g per lb). Spreading it across 3–5 meals of 20–40 g each supports muscle repair.
IIFYM stands for "If It Fits Your Macros". It is a flexible dieting approach where no food is strictly off-limits as long as your daily totals of protein, carbs and fat hit their targets. Most people following it still build their diet mainly around whole, minimally processed foods to cover fibre and micronutrients.
A ketogenic split (around 5% carbs, usually under 50 g a day) is safe for most healthy adults in the short to medium term, but it is restrictive and can raise LDL cholesterol in some people. Anyone with diabetes, kidney disease, a history of eating disorders, or who is pregnant should speak to a doctor first.
Recalculate after every 4–5 kg (about 10 lb) of weight change, when your activity level changes, or if your weight trend has stalled for 2–3 weeks. As you lose weight your TDEE falls, so a deficit that worked at the start becomes smaller over time.
For fat loss, a common starting point is 40% protein, 30% carbs, 30% fat. For muscle gain, try 30% protein, 45% carbs, 25% fat. For general health, the AMDR recommends 10–35% protein, 45–65% carbs, 20–35% fat. Adjust based on your preferences, activity level, and how your body responds. The most important factor is hitting your total calorie target consistently.
Did you know?
Protein has the highest thermic effect of food (TEF) at 20–30%, meaning your body uses 20–30% of protein calories just for digestion and absorption. Carbs use 5–10% and fats use 0–3%. This is one reason high-protein diets aid weight loss.
The IIFYM (If It Fits Your Macros) approach gained popularity in bodybuilding forums around 2010 as a counter to rigid "clean eating" diets. It emphasizes meeting specific protein, carb, and fat targets rather than restricting food choices. The concept is rooted in the law of thermodynamics: body composition changes depend on total calorie and macronutrient intake, not specific food selections.
The recommended daily protein intake for active individuals is 0.7–1.0 grams per pound of body weight, significantly higher than the RDA of 0.36 grams per pound.
Carbohydrates are the body's preferred energy source for high-intensity exercise. Restricting carbs too severely can impair athletic performance.
Dietary fat is essential for hormone production (especially testosterone and estrogen), vitamin absorption (A, D, E, K), and brain function.
Alcohol contains 7 calories per gram but provides no beneficial macronutrients, making it "empty calories."