# Convert a number to equivalent characters

Turn a zero-based index into a spreadsheet-style column name.

Canonical: https://1loc.dev/number/convert-a-number-to-equivalent-characters/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function toChars(n) { return `${n >= 26 ? toChars(Math.floor(n / 26) - 1) : ''}${'ABCDEFGHIJKLMNOPQRSTUVWXYZ'[n % 26]}`; }
```

## Input

```json
27
```

## Expected output

```json
"AB"
```

## Edge case

Input:
```json
0
```
Output:
```json
"A"
```

## Limits

- Zero-based: 0 is A and 25 is Z. The inverse of Convert the name of an Excel column to a number, minus one.

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/convert-a-number-to-equivalent-characters.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.