Tip It is a very clean, simple and fast tip calculator. It is unique in that it provides the option to not include tax in the tip calculation. The interface could not be any simpler to use.
Simply input the total bill, the tax amount, and move the picker to the percentage for the tip. The output is the tip amount and the total bill including tip.
If you would like to include the tax in the calculation for the tip amount, then simply move the slider at the bottom of the screen. All fields update immediately.