How to calculate a tip

Tipping is straightforward math wrapped in a pile of social convention that changes by country, by industry, and by whether you’re in a booth or at the counter. This guide covers the quick mental math for 15/18/20%, how tipping differs country by country, when to tip on pre-tax vs post-tax, how to handle split checks, and the edge cases most people get wrong.

The quick mental math

10%: move the decimal left one place. $47.80 bill → $4.78 tip.

20%: double the 10%. $47.80 → $9.56.

15%: 10% + half of 10%. $47.80 → $4.78 + $2.39 = $7.17.

18%: 20% minus 10% of 20% (i.e., 20% × 0.9). Or just split the difference between 15% and 20%. $47.80 → about $8.60.

For faster mental math on the fly: round the bill up to the nearest $5, take 20%, and you’re typically within $0.50 of the actual 18-20%.

Pre-tax vs post-tax

In the US: tradition is to tip on the pre-tax subtotal, especially in states with high sales tax (California at 7.25%+, Tennessee at 9.5%+). Tipping post-tax inflates your effective tip by ~1-2 percentage points.

In practice most people tip on the total shown, because the subtotal requires mental work. Not a huge deal — pick a convention and stick with it.

Most card readers default to tip on the post-tax total (“Total including tax”). If you want to tip on pre-tax, you may need to enter a dollar amount rather than a percentage.

US tipping standards by industry

Sit-down restaurant: 18-22% standard. 15% is the bare minimum for adequate service and is read as dissatisfaction.

Counter service / coffee shop: 10-15% if tipping; $1-2 per drink is fine. The card-reader prompt for 20-25% at a coffee shop is aggressive — feel free to use “custom” or “no tip.”

Delivery driver: 15-20%, minimum $5 on small orders. Delivery apps often separate this from the “delivery fee” — that fee does not go to the driver.

Taxi / rideshare: 15-20%. Round up for short trips.

Bartender: $1-2 per drink, or 15-20% of the tab if running one.

Hairdresser / barber: 15-20%.

Hotel housekeeping: $3-5 per night, left daily. Leaving a lump sum on the last day typically goes to whoever cleans that day, not the person who cleaned the rest of the week.

Hotel bellhop / valet: $2-5 per bag or car.

Tipping abroad — the rules change

Europe (general): service is often included (“service compris”). A round-up or 5-10% is generous. 20% is wildly excessive in most of continental Europe.

UK: 10-12.5% at sit-down restaurants; often added as “optional service charge” on the bill (check before tipping again).

Japan: no tipping. Attempting to tip can be confusing or mildly rude — the service culture treats it as “your price already includes good service.”

Australia / New Zealand: not expected. Round up or leave a small amount for exceptional service; not a percentage.

China: historically not customary; changing in upscale international hotels but still uncommon in most restaurants.

South Korea: not customary. Tip jars at coffee shops exist but are for loose change.

Middle East (UAE, Saudi): 10% often included as service charge; an additional 5-10% for good service.

Latin America (Mexico, Argentina): 10-15% typical, often on pre-tax; check if “propina” is already on the bill.

Splitting the check — the right way

Even split: take the total (including tip), divide by number of people. Fastest at the table.

Itemized split: each person pays their own items + a pro-rata share of tax and tip. Fairer when orders differ significantly. Apps like Tab or Splitwise handle this; so does our tip calculator with a split field.

If one person is clearly ordering much more (steak vs salad, multiple drinks vs water), itemized is fair. If orders are similar, even-split is faster and avoids nickel-and-diming.

When paying by card with multiple cards: waitstaff can usually split evenly but dislike splitting by item. Do itemized calculations yourself and tell them the per-card amount.

Large-party auto-gratuity

Parties of 6 or 8+ often see an automatic 18-20% gratuity already added to the bill. This should be disclosed on the menu. If it’s included:

You don’t need to tip additionally unless service was exceptional. Adding another 20% on top effectively doubles the tip.

The amount shown on the tip line of the receipt should be $0 or blank (not re-tipped). Some card readers still prompt for an additional tip — it’s OK to leave it blank.

When to tip more (or less)

Tip more: exceptional service, difficult requests accommodated, holidays, end-of-year for regular staff, bad weather for delivery, large parties without auto-gratuity.

Tip less: genuinely bad service. Standard guidance is to still leave 10% and speak to the manager, not zero out — the person may not control kitchen speed, etc.

Never tip 0% as a silent protest — it reads as forgetting, not as a message. If service was unacceptable, say so (kindly) and tip 10% or use management.

Cash vs card

Cash tips typically reach the worker faster (same shift) and in full. Card tips go through payroll and may take 1-2 weeks to hit their account; in some systems, a percentage is withheld for processing fees.

If the bill is on card and you’d like to tip in cash: write “Cash” or zero on the tip line and leave cash on the table.

Run the numbers

Compute tip + per-person split with the tip calculator. Pair with the budget calculator if dining out is a regular line item, and the currency converter when calculating tips in a foreign currency.