Split bill calculator.

Either is normal, and the difference is small. Tipping on the pre-tax subtotal is the stricter reading: the tip is for the service, and tax is not service. Tipping on the post-tax total is what most card terminals suggest, and on a $100 bill with 9% tax it adds about $1.80 at 20%. This calculator tips on the pre-tax subtotal by default, and there is a checkbox to tip on the post-tax total instead. Whichever you pick, the tip is then spread across people the same way.

Switch the calculator to "By what each person had" and enter each person's food and drinks at menu prices, before tax and tip. The calculator adds up those amounts to get the subtotal, works out each person's share of it as a percentage, and gives them that same percentage of the tax and the tip. Someone who ordered $50 of a $100 subtotal pays half the tax and half the tip. That is the fair version of splitting unevenly: nobody subsidises anyone else's steak.

Put it in the "Shared" box. The calculator divides that amount equally between everyone at the table and adds each person's slice to what they ordered themselves, before it works out the proportions. So a $20 appetizer across four people adds $5 to each person's base, and that $5 then carries its own share of tax and tip. If only some people shared something, the simplest fix is to add their portions to those people's own amounts instead.

Use "By what each person had" and leave the birthday person out of the list entirely. Their meal is then covered by everyone else, because the remaining people's amounts are what the calculator divides the tax and tip across. If you want everyone else to cover the birthday meal equally, add its cost to the Shared box: it gets divided evenly between the people who are still in the list, and the birthday person owes nothing.

It goes to whoever is paying the bill. A $100 total split three ways is $33.333 each, and no arrangement of cents makes that come out right. This calculator rounds everyone else to the nearest cent and gives the payer the remainder, so the per-person amounts always add up to the grand total exactly rather than landing a penny over or under. It is the same rule BananaTab uses when it sends requests: friends never get rounded up.

Yes. If the restaurant already added a service charge, mandatory gratuity or large-party fee, set the tip buttons to a custom 0% and put the service charge in the tax box as a dollar amount. It is then spread in proportion to what each person ordered, the same way tax is. If you want to add something on top of a service charge, enter that extra as a tip percentage and it will be calculated on the subtotal as usual.

Yes. Text BananaTab what the bill was and who was there, in plain English, and it does this same math and sends each person a Venmo request for their share. You approve the amounts before anything goes out, and your friends don't need an account or an app to pay. That is the difference between a calculator and BananaTab: the calculator tells you the numbers, BananaTab collects them.