How to split a bill with tax and tip
Split a restaurant bill evenly or by what each person ordered. Proportional split: multiply each person's items by (1 + tax rate + tip rate). Worked example for four people, plus rounding.
For an even split, divide the final total (with tax and tip) by the number of people. For a fair split by order, multiply each person’s food total by one multiplier: 1 + tax rate + tip rate. With 8% tax and an 18% tip on the subtotal, that’s 1.26, so a $48 order costs $60.48.
On this page
Splitting a bill gets awkward when people ordered very different amounts. There are two fair methods, and both take less than a minute.
The example bill
Four friends have dinner. Food subtotal: $172 (Ana $48, Ben $36, Cam $52, Dee $36). Sales tax is 8%, and they tip 18% on the food subtotal.
- Tax: $172 × 0.08 = $13.76
- Tip: $172 × 0.18 = $30.96
- Total: $172 + $13.76 + $30.96 = $216.72
Try it: 18% tip on the $172 food subtotal (before tax)
Open in calculatorThat shows the tip of $30.96. Adding the $13.76 of tax gives the $216.72 total.
Method 1: even split
Divide the final total by the number of people: $216.72 ÷ 4 = $54.18 each.
Try it: Split $216.72 four ways
Open in calculatorThis is simplest when orders were similar. Here, Ben and Dee would pay $8.82 more than their share and Cam $11.34 less.
Method 2: split by what each person ordered
Tax and tip are both percentages of the food, so each person’s share of them is proportional to their order. Combine them into one multiplier:
multiplier = 1 + tax rate + tip rate
Where 1 + 0.08 + 0.18 = 1.26
share = person’s items × multiplier
Where Ana: $48 × 1.26 = $60.48
- Ana: $48 × 1.26 = $60.48
- Ben: $36 × 1.26 = $45.36
- Cam: $52 × 1.26 = $65.52
- Dee: $36 × 1.26 = $45.36
The shares add up to $216.72, the full bill.
When the multiplier needs adjusting
- Tip on the after-tax total. Use (1 + tax) × (1 + tip) instead: 1.08 × 1.18 = 1.2744.
- Service charge already included. Treat it like tax, as part of the multiplier, and don’t add a tip on top unless you mean to. See service charge vs tip.
- Unknown tax rate. Divide the bill’s total by its subtotal to get the multiplier directly: $216.72 ÷ $172 = 1.26.
Rounding
Splitting can leave a stray cent. If the total were $219.95 split four ways, each share is $54.9875, which rounds to $54.99, and four shares come to $219.96. Either one person pays a cent less or the group overpays by a cent. Rounding each share up to a whole dollar avoids the problem and adds a little to the tip.
For the basics of working out the tip, see how to calculate a tip, and for which line to base it on, see tipping before or after tax.
Questions
What if the tip is calculated on the total with tax?
Then the multiplier is (1 + tax rate) × (1 + tip rate) instead of 1 + tax rate + tip rate. With 8% tax and an 18% tip, that’s 1.08 × 1.18 = 1.2744.
How do we handle shared dishes?
Divide the shared item’s price among the people who shared it, add that to their own items, then apply the multiplier as usual.
The calculator links in this guide are checked against the PercentSwift calculator every time the site is built. How we calculate explains the rounding rules. If you spot a mistake, email hello@percentswift.com.
