# Normalize the ratio of a number in a range

Map a value in [min, max] to [0, 1].

Canonical: https://1loc.dev/math/normalize-the-ratio-of-a-number-in-a-range/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function normalizeRatio({ value, min, max }) { return (value - min) / (max - min); }
```

## Input

```json
{
  "value": 75,
  "min": 50,
  "max": 150
}
```

## Expected output

```json
0.25
```

## Edge case

Input:
```json
{
  "value": 200,
  "min": 50,
  "max": 150
}
```
Output:
```json
1.5
```

## Limits

- Values outside the range give ratios outside 0–1. The lab requires min < max.

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/normalize-the-ratio-of-a-number-in-a-range.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: Curated implementation; explicit input contract, edge case and limits. Original MDX retained as inert source evidence.