Answer: Enter your details and the Macro Calculator returns your personalized daily target with the underlying calculation shown step by step.
A macro calculator splits your daily calorie target into protein, carbohydrate, and fat grams in a ratio matched to your goal — cutting, maintaining, or building muscle.
Calculate your protein, carb, and fat targets
Enter age, weight, height, sex, activity level, and goal. The calculator estimates your Basal Metabolic Rate with the Mifflin-St Jeor equation — widely considered the most accurate general-purpose BMR formula — applies your activity multiplier to get Total Daily Energy Expenditure (TDEE), adjusts calories for your goal, then splits those calories into protein, carbohydrate, and fat targets in grams.
The exact math: BMR (men) = 10×kg + 6.25×cm − 5×age + 5; BMR (women) = 10×kg + 6.25×cm − 5×age − 161. TDEE = BMR × activity factor (1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 active, 1.9 very active). The calculator subtracts 400 kcal for weight loss or adds 300 kcal for muscle gain. Protein is set at 2.0 g per kg body weight, fat at 25% of calories ÷ 9 kcal/g, and carbs fill the remainder ÷ 4 kcal/g.
The activity multipliers are the standard Harris-Benedict-derived factors used across nutrition practice: 1.2 for desk jobs with little exercise, 1.375 for 1–3 workouts per week, 1.55 for 3–5, 1.725 for 6–7, and 1.9 for hard daily training or physical jobs. Choosing honestly matters — the multiplier is the biggest source of variance in the final numbers.
The goal adjustments are deliberately conservative: −400 kcal/day is a bit under a pound of fat per week (a pound of fat stores roughly 3,500 kcal), and +300 kcal/day supports gradual muscle gain while limiting fat gain. Aggressive crash deficits lose more lean mass and are harder to sustain.
BMR = 10×75 + 6.25×175 − 5×30 + 5 = 750 + 1093.75 − 150 + 5 = 1,699 kcal. TDEE at moderate (1.55) = 2,633 kcal. Maintain: protein 150 g (2.0 g/kg), fat 73 g (25% of calories), carbs 344 g — the calculator displays each with its calorie share. Lose: 2,233 kcal with the same 150 g protein, 62 g fat, and lower carbs. Gain: 2,933 kcal.
Protein is anchored to body weight rather than calorie intake, so it stays constant across goals — the design choice most evidence-based nutrition coaches use, since protein needs don't drop when dieting.
| Activity Level | Multiplier | Example TDEE* |
|---|---|---|
| Sedentary (desk job) | 1.20 | 2,039 kcal |
| Light (1–3 days/wk) | 1.375 | 2,336 kcal |
| Moderate (3–5 days/wk) | 1.55 | 2,633 kcal |
| Active (6–7 days/wk) | 1.725 | 2,930 kcal |
| Very Active (2×/day or labor) | 1.90 | 3,228 kcal |
Hit protein first (it's the most satiating and muscle-protective), then distribute fat and carbs around preference and training. Timing matters less than daily totals for body composition, though carbs around training support performance. Track with a food scale for a couple of weeks, then adjust: if weight trends wrong by more than ~0.25 kg/week, shift calories 100–200 and recompute.
These are estimates. Real energy expenditure varies between individuals by ±10% or more even with identical inputs (NEAT, genetics, and adaptive thermogenesis). Treat the outputs as a starting hypothesis to refine against scale and mirror data, not a prescription.
Translation to food: 150 g of protein is roughly 500 g of chicken breast (31 g per 100 g) or about six eggs plus two servings of Greek yogurt; 73 g of fat is roughly 2.5 tablespoons of olive oil plus a serving of nuts; 344 g of carbs is about 11 cups of cooked rice — which is why carb targets are usually the easiest to hit incidentally and protein the hardest.
Weigh food raw or cooked consistently, because macros are usually listed per raw gram for meats and per dry or cooked gram for grains — the difference is water, and inconsistent weighing adds error faster than any formula imprecision.
You don't need to track forever. Most people who track successfully for 4–6 weeks internalize portion sizes well enough to eyeball protein at least; keep tracking only the protein anchor and body-weight trend afterwards. And recalculate whenever weight changes by more than about 5 kg, since protein scales with body weight and TDEE with size.
What formula does this macro calculator use?
Mifflin-St Jeor for BMR — 10×kg + 6.25×cm − 5×age + 5 (men) or − 161 (women) — multiplied by a standard activity factor for TDEE. Research has found Mifflin-St Jeor more accurate than the older Harris-Benedict equation for most people.
How much protein should I eat?
This calculator sets protein at 2.0 g per kg of body weight, in line with evidence for active people and dieting (roughly 0.9 g per lb). For a 75 kg person that's 150 g daily, held constant whether cutting or bulking.
How many calories should I cut to lose weight?
The calculator uses a −400 kcal/day deficit — just under a pound per week, since a pound of body fat stores about 3,500 kcal. Faster cuts are possible but lose more lean mass and are harder to sustain.
Do I need to hit macros exactly?
No. Treat them as daily targets with ±5–10 g tolerance. Consistency over weeks matters more than precision at any single meal; protein is the one macro worth prioritizing if you miss the others.
Are TDEE estimates accurate?
Within roughly ±10% for most people. Non-exercise activity, genetics, and metabolic adaptation all shift true expenditure. Use the estimate as a starting point and adjust by 100–200 kcal based on how your weight actually trends over 2–3 weeks.