# Calculate the average of numbers

Divide the sum by the count.

Canonical: https://1loc.dev/number/calculate-the-average-of-arguments/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function averageOf(values) { return values.reduce((a, b) => a + b) / values.length; }
```

## Input

```json
[
  1,
  2,
  3,
  4
]
```

## Expected output

```json
2.5
```

## Edge case

Input:
```json
[
  7
]
```
Output:
```json
7
```

## Limits

- The lab passes one array with at least one number.

The lab validates types and size before calling this function. Add equivalent validation at your own trust boundary.

## Source and license

Original: https://github.com/phuocng/1loc/blob/14b481cf60dff1620ab1bb99a43b1f68068cdd9b/contents/calculate-the-average-of-arguments.mdx
Author: Nguyen Huu Phuoc and original contributors
Contributors: See original repository history
Source commit: 14b481cf60dff1620ab1bb99a43b1f68068cdd9b
Copyright (c) 2020 phuoc-ng
License: MIT — https://1loc.dev/licenses/
Maintainer: Oveyon
Modifications: Takes one array instead of rest arguments. Original MDX retained as inert source evidence.