Is a lookup table the best option?

Using Arduino Programming Questions
8 
const int OneKilo = 327;  //  analogRead() value for a one kilogram test weight, determined experimentally
const int TwoKilos = 561;  // analogRead() value for a two kilogram test weight, determined experimentally
const int countsPerKilo = TwoKilos - OneKilo;
 
int grams(int analogValue)
    {
    analogValue -= (OneKilo - countsPerKilo);  // Remove any offset from 0 weight = 0 volts
    return ((analogValue * 1000) / countsPerKilo);  // Convert voltage to grams
    }