How to Calculate 18 Percent Tip (The 10% + Half Trick)

How to calculate 18 percent tip: multiply the bill by 0.18 — a $50 bill gets a $9 tip. Shortcut: take 10% of the bill, add half of that (5%), then a little more for the 3%. On $60 that's $6 + $3 + $1.80 = $10.80. Check any bill with our free tip calculator; tricks and etiquette below.

The exact method: bill × 0.18

The definition of an 18 percent tip is literal: tip = bill × 0.18. On a $47.50 bill: 47.50 × 0.18 = $8.55. On $112: 112 × 0.18 = $20.16. Keep two decimals while calculating, then round the final total to a clean number — $56.05 on a $47.50 bill, or $56 even if you are feeling generous. Rounding the tip itself to the nearest dollar ($9 on $47.50) is standard practice; nobody expects cents on a tip line. This multiplication is the ground truth every shortcut on this page approximates.

The 10% + 5% + 3% mental trick

No calculator at the table? Break 18% into easy chunks: 10% + 5% + 3%. Take 10% (move the decimal one place left), halve it for 5%, then take roughly a third of the 10% for the last 3%. On $84: 10% = $8.40, 5% = $4.20, 3% ≈ $2.50 → $15.10 (exact: $15.12). On $60: $6 + $3 + $1.80 = $10.80 exactly. The 3% chunk is the only slightly awkward one — “a third of the 10%” is close enough that the error never exceeds a dime on bills under $100. Practice it twice and it becomes automatic; it is the same chunking strategy behind our 20%-in-your-head method.

18% tip cheat sheet ($25–$200)

Memorize three anchors and interpolate: $50 → $9.00; $100 → $18.00; $200 → $36.00. Full table: $25 → $4.50; $30 → $5.40; $40 → $7.20; $50 → $9.00; $60 → $10.80; $75 → $13.50; $80 → $14.40; $100 → $18.00; $120 → $21.60; $150 → $27.00; $200 → $36.00. For odd bills, round to the nearest table row and adjust a little — $86 lands between $80 ($14.40) and $100 ($18), so ~$15.50 is honest (exact: $15.48). Screenshot this table once and the mental math is retired forever.

Tipping on takeout, delivery, and buffets

The 18% rule is a dine-in rule — other formats have their own norms. Takeout: 10% or a few dollars is generous; the kitchen did the work but nobody served you. Tipping 18% on takeout is kind, not expected. Delivery: 15–20% with a $4–5 minimum, more in bad weather — the driver is using their own car and gas, and delivery apps show you the math up front. On a $30 delivery order, 18% is $5.40, right in the zone. Buffets: 10–15%, since you carried your own plate but someone cleared it and refilled drinks. Coffee shops and tip jars: $1 per drink or 10% is plenty; the jar is a nudge, not an invoice. The throughline: tip for service received, and 18% remains the benchmark for full table service — everywhere else, scale to the effort.

When 18% is the right tip (and when it isn't)

So how much to tip at a restaurant in 2026? The US norm has settled into bands: 15% for adequate service, 18% for good service — the default most diners now aim for — and 20%+ for great service. Eighteen percent is also the number restaurants themselves chose: parties of 6–8 routinely get an automatic 18% gratuity, which is the industry's vote for “standard.” Drop below 18% only for genuinely poor service, and tell the manager why — the tip is feedback, not just money. Traveling? Tipping culture changes at the border: much of Europe includes service in the price (rounding up is plenty), Japan considers tipping rude, and US-style percentages apply across North America. If the road trip crosses into metric territory, our miles-to-kilometers converter keeps the driving math honest while the 18% rule keeps the dining math honest. One more modern wrinkle: tip fatigue is real — payment terminals now suggest 20%, 25%, even 30% at counters where 18% was once generous. Those presets are set by the business, not by custom. At a sit-down restaurant, 18% for good service remains the honest benchmark; at a counter, tip what the service earned, preset be damned.

Tip on the pre-tax or post-tax total?

The standard is pre-tax: compute 18% on the subtotal before sales tax. On a $100 subtotal with 8% tax, that is $18.00, not $19.44 — a $1.44 difference the server will never miss and etiquette does not require. In practice most diners tip on the total and nobody minds; the pre-tax rule matters most on large catering bills where the gap becomes real money. Auto-gratuity for big parties is almost always calculated pre-tax, so check the line items before adding extra. Our 20% tip guide covers the before-or-after-tax debate in full.

Splitting an 18% tip among friends

Group dinner, one check: add the tip first, then divide. A $240 bill with 18% tip is $240 + $43.20 = $283.20; among 6 friends that is $47.20 each. The fair rule our bill-splitting guide recommends: split evenly when orders were similar; itemize (each person's subtotal × 1.18, plus their share of tax) when one person ordered the lobster. One person should run the numbers on their phone while the card goes around — volunteers welcome, payment-app requests after.

18% vs 15% vs 20%: what the gap costs

On a $100 bill the bands are $15 / $18 / $20 — a $5 spread between adequate and great. Scale it to a year of dining out: $400/month in restaurants is $4,800/year, and the 15%-to-20% gap is $240 a year — real money, but also the entire difference between “fine” and “the staff remembers your name.” For servers, who often earn a tipped minimum wage, that spread is a meaningful share of income, which is why regulars at a favorite spot tend to live at 20%. Choose your band deliberately rather than defaulting to whatever the payment terminal suggests — those preset buttons start at 20% and climb.

Use the 18% tip calculator

Mental tricks are for the table; exact splits are for the phone. Our free tip calculator takes the bill, applies 18% (or any percentage), adds tax if you want it, and splits the total among your party — the whole splitting workflow in about five seconds. It runs entirely in your browser: no signup, no app install, no “create an account to see your total.” Pair it with the ToolNest homepage — 130+ free tools. The calculator also answers the question every group asks: “what do I owe?” Enter the bill once, set 18%, add tax, enter 6 people — everyone sees $47.20 before the card arrives. No more one person doing math while everyone watches, no more “just put $50 in” overpay. It also handles the awkward cases: two people shared an appetizer, or one person only had a salad — itemize their share first, then apply 18% to each person's subtotal. Five seconds of tapping beats five minutes of receipt archaeology. For everything the evening throws at you, the