Find your Total Daily Energy Expenditure (TDEE) — your BMR combined with your activity level.
TDEE is your BMR multiplied by an activity factor, giving a realistic estimate of the calories you burn on an average day including exercise and daily movement.
BMR is calories burned at complete rest. TDEE adds in activity, exercise, and digestion to estimate your true total daily calorie burn.
It's a reasonable general-purpose starting point, but optimal macro splits vary by goal (muscle gain, endurance, fat loss) and individual preference.