The first step when trying to calculate daily calorie intake is to work out your BMR, or Basal Metabolic Rate. This tells you how much energy your body will use if you were in a state of rest within a 24hr period.
BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
BMR = 655 + ( 9.6 x weight in kilos ) + ( 1.8 x height in cm ) - ( 4.7 x age in years )
BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )
BMR = 66 + ( 13.7 x weight in kilos ) + ( 5 x height in cm ) - ( 6.8 x age in years )
Once you know your BMR, the next step to determine your total daily calorie needs is to multiply your BMR by the appropriate activity factor, based on the amount of movement you do each day:
You can then use this value to work out your macronutrient needs: