Tip Calculator
The rate, the bill, and what you actually hand over.
Runs entirely in your browser
Loading the tool…
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Rate in A, bill in B, total out. It opens on 15% of 50, and the sentence under the answer reads it back so there is no doubt which number is which.
Tip on the pre-tax amount, not the total. Sales tax is not part of the service, and tipping on top of it quietly raises the rate you thought you were paying: on a bill with 9% tax, a 20% tip on the post-tax figure is really about 21.8% of the food. The difference is small on one meal and not on a year of them.
Check for a service charge before adding anything. Many places add 12.5% or 18% automatically, especially for larger tables, and it is easy to tip again on top without noticing. If a charge is already on the bill, the question is whether to add to it rather than what to leave.
Norms differ enormously by country and this tool has no opinion about them. In the United States 18 to 20% is customary for table service; in much of Europe rounding up or 5 to 10% is normal because service is priced in; in Japan tipping can be actively unwelcome. The arithmetic is the same everywhere and the rate is your business.
How to use it
- Put the rate in A and the amount in B. The answer updates as you type.
- Read the sentence underneath to check it says what you meant.
- Change the question in the menu for any of the other three.
Questions
Should I tip on the pre-tax or post-tax total?
Pre-tax. Tax is not part of the service and tipping on it raises the effective rate: with 9% sales tax, a 20% tip on the post-tax total works out at about 21.8% of the food. Plenty of people do it either way and nobody will comment, but the honest figure is the one before tax.
How do I split a bill with the tip included?
Work out the total here, then divide it by the number of people rather than splitting the bill and the tip separately, which is where rounding goes astray. If everyone ate very differently, split the food by what each had and the tip in proportion to it.
What if a service charge is already on the bill?
Then the tip is already there, usually at 12.5% or 18%, and adding a full one on top means paying twice. Check the itemisation before assuming. Adding a little more for genuinely good service is a choice rather than an expectation, and a service charge can normally be removed if the service was poor.
How much should I tip?
It depends entirely on where you are and this page will not tell you. In the United States 18 to 20% is customary for table service. In much of Europe service is included and rounding up is enough. In Japan and South Korea tipping is not the custom and can cause confusion. Change the rate to whatever is right where you are.
Is my calculation sent anywhere?
No. The arithmetic runs in WebAssembly in this tab and the page is served with a header forbidding it from opening a connection to anywhere. Nothing you type is recorded, and it works with the network off.
The other one
The same calculator opened on a different question. Both take any rate and any amount once you are there.
Your data stays on your device
Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. You can load this page once, go offline, and it still works.
This page makes no requests at all, to anywhere. That is not a promise in the copy: it is a Content-Security-Policy header your browser enforces, and connect-src on it is none. Open the network tab and watch nothing happen.