How much salt and pink salt do I need for pork sausage?
According to Smoking Meat Forums, you would need 2 ounces of pink salt for 50 lbs of sausage, which is a ratio of 0.0025 pink salt to meat (they provide three significant digits) for short curing time sausages.  These are sausages which will be cooked or smoked.

Therefore, converting to metric, 50 kg, you would require 125 grams or so pink salt.  

Note that the regular salt is not really a curing agent at concentrations used in this type of sausage, but for flavor and texture:


  Although salt is not generally used in concentrations sufficient to
  effect preservation it exerts some antimicrobial activity. Some
  bacteria are already inhibited at 2 percent levels of salt. Other
  microorganisms tolerate a much higher concentration of salt.


You would need to provide an original recipe or formula on which you have based your calculations to get any validation of your computation of the regular salt amount.

See also:


How to dry homemade pork sausages with proper humidity and temperature?
Rhulman on meat curing safety issues