---
title: "Permutation & Combination"
method: GET
path: "/api/calc/permutation-combination-calculator"
tags: ["Math"]
---

# Permutation & Combination

`GET /api/calc/permutation-combination-calculator`

## Request

- Base URL: `https://calcbright.com`
- URL: `https://calcbright.com/api/calc/permutation-combination-calculator`
- Auth: none declared

Choosing 3 from 10 items gives 720 ordered arrangements (nPr) or 120 combinations (nCr). Get both, plus repetition cases and n factorial, with exact big numbers.

## Query parameters

- `n` number: Total items (n)
- `r` number: Items chosen (r)

## Response `200`

Calculation result

- CalcOutput
  - `ok` boolean
  - `tool` string
  - `name` string
  - `url` string: Open this link to see the full calculation
  - `inputs` object
  - `summary` string: Plain-text answer
  - `details` string
  - `result` object
  - `errors` object

## Other responses

- `400`: Invalid input (see errors)

---

[API](https://skmtc.dev/calcbright/apis/calcbright-calculator-api.md) · [All operations](https://skmtc.dev/calcbright/apis/calcbright-calculator-api/llms.txt) · [OpenAPI document](https://skmtc.dev/calcbright/apis/calcbright-calculator-api/revisions/f58229e56e58?raw)