A very simple idea: when you eat more than your maintenance calories, you gain weight; when you eat less than your maintenance calories, you lose weight.By using an algorithm, we can accurately figure out your maintenance calories more accurately than traditional regression based formulas like katch mc ardle.It s way more accurate than calorie burn tracking devices like fitness bands and watches. (garmin/apple watch/whoop etc...)Traditionally, people often use static TDEE calculators which often over or underestimate for some by 100s calories.Chatgpt and TDEE calculators like Calculator.net or TDEECalculator.net use the same formulas, so they share the same limitationIf a beginner asks ChatGPT, What are my maintenance calories? , ChatGPT can give them a number. But ask how it arrived at that number, and it will usually explain that it used a formula like Katch McArdle, Harris Benedict, or Mifflin St Jeor to calculate BMR, then layered activity on top using an activity factor, PAL, or MET tables.Dig deeper and those formulas come from statistical regressions based on averages from past populations. That means maintenance calories calculated this way can be off by hundreds of calories.MacroCodex uses your calorie intake and weight data to figure out maintenance calories specific to your body, not the population average.It usually reaches good accuracy after about 3 weeks, or 21 days of calorie and weight logging.This app is completely free, no paywall, no subscription and no ads. (works offline)Most people start seeing weight gain or loss within 5 weeks.We ve reached 13,000+ users. Full support is provided if you experience any issue, most issues are resolved under 24 hours.