Guide · Restaurant tipping
The tip is supposed to be on the bill before tax
Almost every tip calculator, app and mental-math shortcut runs its percentage on the number printed at the bottom of the check — the one that already includes sales tax. Emily Post’s own published guidance says that number is the wrong one to use.
The short answer
Emily Post’s General Tipping Guide doesn’t just publish a percentage for sit-down restaurant service — it publishes a percentage anda base to calculate it from, in the same two words: “pre-tax.” sourced Sales tax is money the restaurant collects for the state, not a service anyone at the table performed — tipping on top of it quietly tips the tax itself.
The rule, in its own words
The Emily Post Institute’s General Tipping Guide lists each service category with a figure and, where it matters, a base. Two rows carry the same instruction: sourced
Wait service (sit down): “15-20%, pre-tax.”
Wait service (buffet): “10%, pre-tax.”
Both rows specify the base the percentage applies to, not just the percentage — and in both cases it’s the food and drink total before sales tax is added, not the number at the bottom of the printed check.
Why it matters, in dollars
The gap is proportional to the local sales tax rate, so it scales with the check and with where you’re eating. On a $100 pre-tax bill in a city with an 8% sales tax, the total on the receipt is $108. Tip 18% on $100 and it’s $18. Tip 18% on $108 instead — the instinctive read of “18% of the bill” — and it’s $19.44: an extra $1.44 that has nothing to do with the service and everything to do with the tax rate in that state. house judgment— the pre-tax base is Emily Post’s; this worked example is ours.
It isn’t a large error on any single check. It compounds the same way over every meal out, in the same direction every time — because sales tax is never subtracted, the error only ever adds, and it’s larger exactly where sales tax is higher.
What this doesn’t mean
- It doesn’t mean tipping on the post-tax total is wrong or rude. It’s simply a larger tip than Emily Post’s own published guidance calls for — plenty of guests tip more than the published floor on purpose.
- It doesn’t apply to every row in the same guide. Not every service category names a base the way the two wait-service rows do — this guide reports what those two specific rows say, not a blanket rule for every kind of tipping.
- It doesn’t change what a service charge already on the check is. A mandatory service charge added by the restaurant is a separate question, governed by IRS guidance and 29 CFR 531.55 rather than this pre-tax instruction — it’s the restaurant’s revenue either way, calculated however the restaurant set it.
So what does the table actually owe?
The bill split calculator starts every tip from the pre-tax total automatically — then splits the check by whatever rule the table actually wants, to the cent, and prints what tipping on the full total would have cost as its own line.
Split the check →Sources
- The Emily Post Institute — General Tipping Guide — the wait-service sit-down and buffet rows, both specifying a pre-tax base, quoted above.
Informational only. This guide reports Emily Post’s published tipping guidance and labels our own worked example as ours. Tipping norms vary by region and situation, and this guide reports one publisher’s guidance rather than a universal rule. Last reviewed: August 2026.
More on how KindHow separates a source from a house call: the published methodology. Every guide is listed on the guides index.