flexi cart - A comprehensive shopping cart library for CodeIgniter

[eluser]haseydesign[/eluser]
Hey GhostPepper,

I think you've made a small error in your calculations.
Your example of removing 20% from 74.45 returning 14.89 (74.45 * 0.2) is not how you calculate tax.
For example, 100 + 20% = 120, but 120 * 0.2 = 24 rather than 20.

Another point that would cause you further error, is that the price for items #102 is 74.45 plus the shipping cost which also in this example includes tax. So you would need to calculate 20% of (74.45 + 3.95), which equals 13.07.

Have a quick read of http://www.simetric.co.uk/si_deduct_tax.htm to get a little more detail.