I developed a Tip Calculator for calculating the tip on the pre-tax subtotal. The calculator calculates the tip and tax separately using the subtotal as the base and then adds both values to the subtotal. Tip and tax are calculated independently of each other and tip does not include tax (nor vice-versa). Default tax included is Canadian HST.

 

• The tip calculator is optimized for iOS and is hand-coded in jQuery/Javascript
• The total auto-updates live as the values for each change—no need to press a submit button!
• It is a web app that runs in Mobile Safari.

 

You can see more screenshots and a link to the source code here.

 

Or you can try it out for yourself at onlycode.ca/tip. Add this useful app-enabled tool to your iPhone's home screen so you can access it like an app whenever you're out and need to tip.