# How do we split the bill?

Splits a restaurant bill with tax and tip evenly between people, or by what each person ordered with shared dishes split evenly and tax and tip in proportion.

- Page: https://www.acalculator.org/everyday-life/bill-split-calculator
- JSON spec: https://www.acalculator.org/everyday-life/bill-split-calculator.json
- Version: c8da105c5cfd

## Default answer

Example with the default inputs (Split Evenly, Bill before tax and tip $120.00, People 4, Tip 18%, Round each share Exact): The total is $141.60. Each of 4 pays $35.40.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| mode | Split | Evenly between everyone, or by what each person ordered. |
| bill | Bill before tax and tip | The food and drink total on the bill, before tax and tip. |
| people | People | How many people share the bill. |
| orders | What each person ordered | One row per person: the total of their own food and drinks, before tax and tip. |
| shared | Shared dishes | Dishes everyone shared, split evenly. Leave empty for none. |
| tax | Tax | The tax on the bill, in dollars. Leave empty for none. |
| tip | Tip | The tip as a percent of the bill before tax. |
| round | Round each share | Leave each share exact, or round it up to the next whole dollar (the extra goes to the tip). |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| total | Total to pay | Food and drinks + tax + tip (with any rounding up). |
| split | Who pays what | Each person’s share: the even share, or each person’s food, part of the shared dishes, tax and tip. |
| share | Each person pays | The even share of the total (even split only). |
| food | Bill before tax and tip | The food and drink total. |
| tipAmount | Tip | Tip % × the bill before tax, plus any rounding up. |
| taxAmount | Tax | The tax on the bill. |

## Method

Tip = tip % × bill before tax; each share = own food (+ shared ÷ people) × (1 + tip %) + tax × own food ÷ total food; total = sum of shares.

## Assumptions

- The tip is on the bill before tax. Shared dishes are split evenly; tax and tip follow each person’s food.
- Each share is rounded to the cent for display, so the shown shares can differ from the total by a cent.

## Worked examples

1. mode = even, bill = $120.00, people = 4, tax = $9.60, tip = 18%, round = no gives tipAmount = $21.60, total = $151.20, share = $37.80, split = Each of 4 pays $37.80. Source: OpenStax, Prealgebra 2e, §6.2 Solve General Applications of Percent (tip and tax as a percent of an amount). https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent.
2. mode = items, orders = {"amount":25} or {"amount":32.5}, shared = $12.00, tax = $7.00, tip = 20%, round = no gives food = $87.50, total = $112.00, tipAmount = $17.50, split = Person 1: $37.12; Person 2: $46.72; Person 3: $28.16. Source: OpenStax, Prealgebra 2e, §6.2 Solve General Applications of Percent (tip and tax as a percent of an amount). https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent.
3. mode = even, bill = $85.40, people = 3, tip = 20%, round = up gives share = $35.00, total = $105.00, tipAmount = $19.60. Source: OpenStax, Prealgebra 2e, §6.2 Solve General Applications of Percent (tip and tax as a percent of an amount). https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent.

## FAQ

### How do I split a bill evenly with tip?

Add the tip (tip % × the bill before tax) and the tax to the bill, then divide by the number of people. A $120 bill with $9.60 tax and an 18% tip is 120 + 9.60 + 21.60 = $151.20, or $37.80 each for four people.

### How do I split a bill by what each person ordered?

Give each person their own food plus an even part of any shared dishes. Then add their part of the tip (the tip % of their food) and of the tax (the tax × their food ÷ all the food). The shares add up to the whole bill.

### Why is the tax split in proportion?

Tax is charged on the food, so a person who ordered more pays more of it. Someone with $29 of a $87.50 bill pays 29 ÷ 87.50 of the tax: $2.32 of $7.

### Should the tip be on the bill before or after tax?

This calculator tips on the bill before tax, which is the usual custom. To tip on the amount after tax, raise the tip percent a little.

### What does rounding up do?

Each share goes up to the next whole dollar, and the extra is added to the tip. Three shares of $34.16 become $35 each, so the tip grows from $17.08 to $19.60.

### Why do the shares not add up to the total exactly?

Each share is shown to the cent, so a split such as $100 three ways shows $33.33 each. The total is exact; one person can pay the leftover cent.

## Sources

- OpenStax, Prealgebra 2e, §6.2 Solve General Applications of Percent (an amount as a percent of a base, as for a tip or a tax). https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent (retrieved 2026-10-02)