We have a shopping cart that is used in different places, therefore the tax is stored in a config file, presently in New Zealand it is 15%, so in the config file we are storing .15 but this number can be changed, so I need to formulas to not rely on this value being a specifc value! We also have another key that stores whether the prices we are storing are tax inclusive or exclusive (users are picky, some want to enter prices with, some without...
Originally asked by Hailwood on Stack Exchange (stackoverflow) (CC BY-SA 3.0).
