# Tip Calculator

> Computes the tip from a bill amount and tip percentage, the total including tip, and the per-person share when the bill is split evenly.

- Calculator id: `tip` · Category: Finance (`finance`) · Tool name: `calculate_tip`
- Canonical page: https://tttkmbb.com/finance/tip · This document: https://tttkmbb.com/finance/tip.md · JSON definition: https://tttkmbb.com/finance/tip.json

## Purpose

Computes the tip from a bill amount and tip percentage, the total including tip, and the per-person share when the bill is split evenly.

**Use when:** You need to add a gratuity to a restaurant, delivery or service bill and optionally divide the total among several people.

**Do not use when:** People pay for different items or unequal shares (use bill-split), or you need to add sales tax rather than a tip (use sales-tax).

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `bill_amount` | number |  | required | Amount on the bill before tip (pre- or post-tax, as you prefer to tip). (min 0, max 10000000) |
| `tip_percent` | number | % | optional, default 15 | Gratuity as a percent of bill_amount. US restaurant custom is 15–20 %. (min 0, max 100) |
| `split_between` | integer |  | optional, default 1 | How many people share the bill equally. (min 1, max 1000) |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `tip_amount` | number |  | bill_amount × tip_percent / 100. |
| `total_amount` | number |  | bill_amount + tip_amount. |
| `total_per_person` | number |  | total_amount / split_between. |
| `tip_per_person` | number |  | tip_amount / split_between. |
| `bill_per_person` | number |  | bill_amount / split_between. |

## Formula

`tip_amount = bill_amount × tip_percent / 100; total_amount = bill_amount + tip_amount; per person = value / split_between`

## Data Sources

- Wikipedia – Gratuity (tipping customs by country) — https://en.wikipedia.org/wiki/Gratuity (reference, retrieved 2026-09-23)
- Wikipedia – Percentage — https://en.wikipedia.org/wiki/Percentage (reference, retrieved 2026-09-23)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/tip?bill_amount=…`
- `POST https://tttkmbb.com/api/v1/calculate/tip` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/tip · OpenAPI operationId `calculate_tip` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool: `calculate_tip` (dedicated) or `run_calculator` with `{"calculator_id": "tip", "inputs": {…}}`

## Example

- 85.50 bill, 18 % tip, 3 people: inputs `{"bill_amount":85.5,"tip_percent":18,"split_between":3}` → `{"tip_amount":15.39,"total_amount":100.89,"total_per_person":33.63,"tip_per_person":5.13,"bill_per_person":28.5}`
- 42.00 bill, 20 % tip: inputs `{"bill_amount":42,"tip_percent":20}` → `{"tip_amount":8.4,"total_amount":50.4,"total_per_person":50.4}`

```
GET https://tttkmbb.com/api/v1/calculate/tip?bill_amount=85.5&tip_percent=18&split_between=3
```

## Limitations

People pay for different items or unequal shares (use bill-split), or you need to add sales tax rather than a tip (use sales-tax). All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**Should I tip on the pre-tax or post-tax amount?**

Custom in the US is to tip on the pre-tax subtotal, though many people tip on the total; enter whichever amount you want the percentage applied to.

**What are typical percentages?**

US sit-down restaurants 15–20 %, exceptional service 20–25 %, counter service 0–10 %. In many countries (Japan, much of Europe) service is included and tipping is small or absent.

## Related

- [Bill Split Calculator](https://tttkmbb.com/everyday/bill-split.md) — Divide a bill unevenly or itemise it among people.
- [Sales Tax Calculator](https://tttkmbb.com/finance/sales-tax.md) — Add sales tax to a price.