The Tip Formula
Calculating a tip is one line of math: Tip = bill subtotal x tip percentage. On a $64.50 bill at 20%, that is 64.50 x 0.20 = $12.90. Total: $77.40.
For mental math, use the decimal trick. Move the bill's decimal point one place left to get 10%: $64.50 becomes $6.45. Double it for 20%: $12.90. For 15%, take the 10% number and add half of it ($6.45 + $3.23 = $9.68, round to $9.70). Rounding up to the nearest dollar is standard and keeps cash tips simple.
One rule that matters: tip on the pre-tax subtotal, not the total with tax. Tax rates vary by city and have nothing to do with the service you received, so base your percentage on the food and drink before tax.
How Much to Tip: US Etiquette
Norms have drifted upward over the years. Current expectations in the US: 18-20% for standard sit-down restaurant service, with 20% the common default. Exceptional service earns 22-25%. 15% is fine for casual or counter service, buffet lines, and takeout where staff just hand you food. 10% signals you were unhappy with the service.
Beyond restaurants: tip bartenders $1-2 per drink or 15-20% of the tab, baristas $1-2 or about 10-15%, delivery drivers 15-20% with a $3-5 minimum, rideshare drivers 10-20%, and haircuts 15-20%. For large restaurant parties (usually 6-8 people), many places add an automatic gratuity of 18-20%, so check the bill before tipping on top of it.
Tablet tip screens at coffee shops and takeout counters have created real tip fatigue, and it is fine to tip less there or not at all when no real service was involved. The screen defaults (often 20-25-30%) are designed to nudge you upward. A dollar or two for a quick counter transaction is generous and normal; save the full percentage for places where someone is actually serving you.
Splitting the Bill
The cleanest method for an even split: add the tip to the full bill, then divide by the number of people. A $240 bill plus a 20% tip ($48) is $288; split four ways, everyone pays $72.
When orders are lopsided, one person ordering the steak and wine while others get salads, even splits cause resentment. Instead, split by subtotal: each person pays their own items plus the same tip percentage on their items. Tax follows each person's share. It takes a minute longer, but it keeps friendships intact.
Watch for two traps. First, double-check that a service charge or large-party gratuity is not already on the bill before adding your own tip. Second, when splitting, decide up front whether one person puts the card down and gets reimbursed, or everyone pays separately, because sorting that out at the table is how the night ends badly.
Frequently Asked Questions
What is the standard tip percentage in the US?
18 to 20 percent is the current standard for sit-down restaurant service in the US, with 20 percent the common default. 15 percent is acceptable for counter or casual service, and 10 percent or less signals poor service.
Do you tip on the pre-tax or post-tax total?
Tip on the pre-tax subtotal. Tax varies by location and is not part of the service you are tipping for, so calculate the percentage on the food and drink total before tax.
How do you split a restaurant bill evenly?
Add the tip to the full bill, then divide the total by the number of people. If the group is uneven (one person ordered much more), split by each person's itemized subtotal plus a proportional share of the tip instead.
Should you tip when the service was bad?
Yes, tip something. If the problem was the server, 10 percent signals dissatisfaction without stiffing them; if the problem was the kitchen or management, do not punish the server and consider speaking to a manager.