Calorie & Macro Calculator
Calculate your maintenance calories, fat-loss target, and macro split from your lean body mass using the Katch-McArdle method, the same body-composition-based formula we use with coaching clients.
That's roughly 5 chicken breasts of protein, 4 bowls of rice of carbs, and 4 tbsp olive oil of fat across your day.
≈ 677 kcal/day below maintenance, about 0.61 kg of fat per week. Protein is set from your lean mass to protect muscle in the deficit.
Want a plan built around these numbers?
These are estimates. We build yours from weekly data, not formulas.
The method behind the numbers
- 1
Enter your bodyweight and body-fat %, we subtract fat mass to find your lean body mass (LBM), the engine of your metabolism.
- 2
Your resting metabolic rate is calculated with the Katch-McArdle formula (21.6 × LBM + 370), which is more accurate than weight-only equations because it accounts for how much muscle you carry.
- 3
Maintenance calories = RMR × your activity multiplier. Your fat-loss target subtracts a daily deficit set by your chosen weekly rate (0.5–1% of bodyweight).
- 4
Macros are built to protect muscle: protein from your lean mass (2.0–2.8 g/kg), fat as a share of calories, and the rest from carbs.
Common questions
How are my calories calculated?+
We use the Katch-McArdle equation, which bases your resting metabolic rate on lean body mass rather than total weight. Maintenance is that RMR multiplied by an activity factor, and your fat-loss target subtracts a daily deficit derived from your chosen weekly loss rate.
Why does it ask for body-fat percentage?+
Two people at the same weight can have very different amounts of muscle. Because muscle drives metabolism, using lean body mass gives a far more accurate calorie and protein target than weight-only calculators.
How much protein should I eat to lose fat?+
In a deficit, protein protects muscle. This tool sets protein from your lean body mass, typically 2.0 to 2.8 grams per kilogram of lean mass, which is higher than general guidelines because you're dieting.
Is losing 0.5–1% of bodyweight per week realistic?+
Yes. A gentle 0.5%/week is most sustainable and best preserves muscle; 1%/week is faster but harder to maintain. The calculator shows the exact daily deficit and weekly kg for each pace.
Do I need to know my exact body-fat percentage?+
A reasonable estimate is fine, even a rough figure makes the result more accurate than ignoring body composition entirely. For a precise number, our coaches measure it weekly in-studio.
You have the numbers. Here's what to do with them.
A calculator tells you where you stand. Our free guide shows you how to act on it, and a free consultation turns it into a plan built around you.