Every macro calculator on the internet asks the same five questions and produces a number that is, on day one, almost certainly wrong. That is not a flaw. It is the design. A macro target is a hypothesis you test for two weeks, not a verdict the universe handed down.
How the number is built
Most calculators run a Mifflin-St Jeor estimate of your basal metabolic rate, multiply it by an activity factor, and split the resulting calories across protein, carbs and fats using a ratio you choose or the calculator chose for you. The math is simple. The inputs are not.
Activity factor is the largest source of error. People wildly overestimate their daily movement, and the difference between “lightly active” and “moderately active” can be 400 calories. Two equally honest people will plug the same goal into the same calculator and walk away with very different numbers.
The starting points worth remembering
Protein: 1.6 to 2.2 grams per kilogram of body weight, every day, for almost everyone trying to change body composition. Fats: at least 0.6 grams per kilogram, lower than that and hormones complain. Carbs: whatever calories are left over. That is the entire framework.
How to adjust
Track for two weeks. Average your weekly weight at a fixed time, fasted, on the same day each morning. If you are aiming for fat loss and the trend has not moved by 0.3 to 0.5 kilograms per week, drop daily calories by roughly 150. If muscle gain is the goal and weight has been flat for three weeks, add 150. Hold the new number for another two weeks. Repeat.
The mistake most people make
Adjusting after a single bad weigh-in. A daily fluctuation of one to two kilograms is normal. It is salt, glycogen, sleep, hormones, weather. Decisions made on Tuesday’s number are decisions made on noise. Use trend lines.
How Enerium handles this
We set targets using the same Mifflin-St Jeor base, then learn from your actual logged adherence and weight trend over the first few weeks and quietly recalibrate. You can see the adjusted target and override it. The point is to give you a number that gets less wrong over time, instead of one frozen the day you signed up.