The check comes, the card reader spins around, and suddenly you’re doing math in public. These shortcuts take the pressure off. They all start from one easy number: 10%.
The short version
- 10%: move the decimal one place left. $48.00 → $4.80.
- 20%: double the 10%. $4.80 × 2 = $9.60.
- 15%: 10% plus half of it. $4.80 + $2.40 = $7.20.
- 18%: 20% minus 2% (a fifth of 10%). $9.60 − $0.96 = $8.64.
Step 1: Find 10%
Move the decimal point one place to the left. On $63.40, 10% is $6.34. Round it to $6.30 or $6.35 if that makes the rest easier.
Step 2: Build the tip you want
- 20%: double 10%. On $63.40: $12.68.
- 15%: add half of 10% to 10%. $6.34 + $3.17 = $9.51.
- 18%: take 20% and subtract 2% (which is 10% ÷ 5). $12.68 − $1.27 = $11.41.
- 25%: divide the bill by 4. $63.40 ÷ 4 = $15.85.
Tip table
| Bill | 15% | 18% | 20% |
|---|---|---|---|
| $20 | $3.00 | $3.60 | $4.00 |
| $35 | $5.25 | $6.30 | $7.00 |
| $48 | $7.20 | $8.64 | $9.60 |
| $60 | $9.00 | $10.80 | $12.00 |
| $85 | $12.75 | $15.30 | $17.00 |
| $120 | $18.00 | $21.60 | $24.00 |
| $150 | $22.50 | $27.00 | $30.00 |
Before tax or after?
Most people calculate the tip on the subtotal before tax. Tipping on the total after tax is slightly more generous. On an $85 bill with 8% tax, 20% before tax is $17.00; after tax it’s $18.36. Either is fine; just be consistent.
Watch for a service charge
Many restaurants add an automatic service charge or gratuity for large groups, and some add one to every bill. Read the receipt before tipping. Under IRS rules, a mandatory service charge is not a tip, which also matters for servers claiming the new federal tips deduction; see no tax on tips.
Splitting the tip
In a group, work out the tip on the whole subtotal and split it with the bill, or have each person tip on their own share. Our guide to splitting a bill shows both ways.
Example
Carmen’s dinner in Denver comes to $63.40 before tax. She wants to leave 20%: 10% is $6.34, doubled is $12.68. She rounds to $13 so the total is easy, and the card reader’s “20%” button (calculated on the post-tax total) would have suggested slightly more.
Tip screens
Card readers often suggest percentages calculated on the total after tax, and some start at 20% or higher. You can always choose a custom amount. Use the shortcut above to decide what you meant to leave.
For an exact number, our tip calculator splits the bill too, and you can type “20% tip on 63.40” into our Quick Answers box.
Tips beyond restaurants
The same shortcuts work anywhere you tip a percentage: food delivery, rideshare, hair salons, taxis. For services usually tipped in flat amounts, such as hotel housekeeping or coat checks, the math is simpler but the habit is the same: decide in advance and keep small bills on hand.
Rounding to make it easy
Many people round the tip so the total is a whole dollar. On a $63.40 bill with tax of $5.07 (8%), a 20% pre-tax tip of $12.68 brings the total to $81.15. Tipping $12.53 instead makes the total an even $81.00, and $13.53 makes it $82.00. Small rounding choices cost or save cents, so pick whatever makes the receipt easy to read.
Tipping on a discounted bill
If you use a coupon or a gift card, many people tip on the amount before the discount, since the server did the same work. On a $60 meal with a $20 off coupon, a 20% tip would be $12 on the full price rather than $8 on the discounted $40.
Splitting the tip among a group
Example
Six friends share a $210 dinner before tax. A 20% tip is $42, or $7 each. If the bill is split by what each person ordered, each person’s tip is 20% of their own items instead; our split bill calculator does both.
