Tipping 15% used to be the standard advice in US restaurant etiquette guides through the 1990s. By the 2010s, most guides had shifted to 18–20% as the baseline for adequate service, with 20%+ for excellent service. The percentage crept upward gradually, driven by rising menu prices, low base wages for tipped workers in the US, and a general upward drift in service-industry expectations — not by any single rule change.
Why Restaurants Use a Percentage Instead of a Flat Fee
A percentage-based tip scales with the value of the meal, which loosely correlates with the complexity of service — a $200 group dinner with multiple courses generally requires more server effort than a $20 solo lunch. It is an imperfect proxy (a $200 bottle of wine adds cost but not much server effort), which is part of why some upscale restaurants have shifted to a flat service charge instead of an expected tip.
The Mental Math Shortcut
For 20%, the fastest mental calculation is: find 10% (move the decimal point one place left), then double it. A $64.50 bill: 10% is $6.45, doubled is $12.90. For 15%, find 10%, then add half of that 10% figure: $6.45 + $3.23 = $9.68. For 18%, find 10%, double it for 20%, then subtract 2% (one-fifth of the 10% figure): $12.90 − $1.29 = $11.61.
Tip on Pre-Tax or Post-Tax Total?
Etiquette guides are split, but the practical convention in the US is to tip on the pre-tax subtotal, since sales tax is a government charge unrelated to service quality. The difference is usually small — on a $100 bill with 8% sales tax, tipping 20% on $100 versus $108 is a $1.60 difference — but it adds up over many visits.
Splitting a Tip Is Not Always Splitting It Evenly
When a group splits a bill evenly, including the tip, the convention assumes everyone ordered roughly the same value of food. If one person ordered a $12 salad and another ordered a $45 steak with three cocktails, an even split of the tip means the salad-orderer subsidizes the steak-orderer's service tip. The mathematically "fair" approach is to tip proportionally to each person's own subtotal, then sum those individual tips — which produces the same total tip amount as a percentage of the full bill, just distributed differently across the group.
What Happens When a Service Charge Is Already on the Bill
Many restaurants add a service charge automatically, often 12.5% in the United Kingdom or 18 to 20% for larger parties in the United States. That charge is the tip. Adding another 20% on top means paying roughly double, which is a common and expensive mistake when the line item is buried near the tax.
Read the itemised bill before calculating anything. If a service charge appears, the decision is whether to adjust it rather than whether to add to it, and in most places it can be removed on request if the service was poor.
Tipping Norms Are Not Universal
The percentage that feels standard is a local convention, not a rule of arithmetic. In Japan, tipping is not practised and leaving money can cause genuine awkwardness. Across much of continental Europe, service is included by law and rounding up the bill is the normal gesture. In Australia and New Zealand, tipping is occasional rather than expected because minimum wages in hospitality are considerably higher.
The United States sits at the other end because the federal tipped minimum wage has been 2.13 dollars an hour since 1991, with tips expected to make up the difference. That single piece of wage policy is why the American percentage keeps climbing while other countries stay flat.
Card Tips, Cash Tips, and Who Actually Receives Them
A tip left on a card passes through the payment processor, which takes its percentage of the total including the tip. Where tips are pooled, the amount is then split across the front of house and sometimes the kitchen according to a house policy the customer never sees.
Cash reaches staff faster and in full, which is why some servers prefer it. Neither choice changes what you owe, but it does change how much of it arrives.
Frequently Asked Questions
Should I tip on the pre-discount or post-discount total?
On the pre-discount total. A voucher or a happy-hour price reduces what you pay, not the work the server did. Calculating 20% of the full menu value is the convention, and on a half-price offer the difference is significant to the person serving you.
Is 15% still acceptable?
In the United States 15% now reads as a signal that something went wrong, with 18 to 20% treated as ordinary and more for genuinely good service. The band has shifted upward over about two decades, largely because the tipped minimum wage has not moved.
How do I split a bill when people ordered very differently?
Splitting evenly is simple but pushes the cost of an expensive order onto everyone else. The fairer approach is to total each person's items, apply the same tip percentage to each subtotal, and add a share of tax proportional to what they ordered.
Do I tip on delivery orders?
Delivery is normally tipped, and the driver often receives little of the delivery fee itself, which usually goes to the platform or the restaurant. A percentage works for large orders while a flat amount is more common for small ones, since 20% of a modest order is not worth the trip.
What is the quickest way to work out 20% in my head?
Move the decimal point one place left to get 10%, then double it. On a bill of 84.60, that is 8.46 doubled to 16.92. For 18%, take the 10%, halve it for 5%, add three-fifths of that again — or accept that rounding to 17 is close enough for anyone.
Related tools worth having open at the table: the discount calculator for working out the pre-discount value, the sales tax calculator for separating tax from the subtotal, and the rest of the everyday calculators.
Use the Tip Calculator to compute the tip amount, total bill, and per-person split instantly — including uneven splits where each diner pays based on their own order.