Tip + tax split calculator

Tip + tax math without the table-side scramble

When you know the subtotal, the restaurant tax rate, and the tip rate, the check math is deterministic:

• Sales tax = subtotal × tax rate
• Tip = tip base × tip rate
• Grand total = subtotal + sales tax + tip
• Per person = grand total ÷ split count

Subtotal tip vs post-tax tip

Most U.S. diners tip on the pre-tax subtotal. That keeps the gratuity tied to the food and service rather than to the local tax code. But some people prefer tipping on the taxed total because it is easier when scanning the final receipt. If your tax rate is 8.25% and you tip 20%, that choice changes the tip by 1.65% of the subtotal.

Quick examples

• $100 subtotal, 8.25% tax, 20% tip on subtotal = $128.25
• Same inputs, 20% tip on taxed total = $129.90
• Split 3 ways on the first example = $42.75 each

Large-party service charges

If the restaurant already added an automatic gratuity, treat that service charge as the tip line before you add anything extra. Otherwise you can accidentally double-tip by stacking a full percentage tip on top of an included gratuity.