modeling-app/docs/kcl-std/functions/std-units-toMillimeters.md

---
title: "units::toMillimeters"
subtitle: "Function in std::units"
excerpt: "Convert a number to millimeters from its current units."
layout: manual
---

Convert a number to millimeters from its current units.

```kcl
units::toMillimeters(@num: number(mm)): number(mm)
```


### Arguments

| Name | Type | Description | Required |
|----------|------|-------------|----------|
| `num` | `number(mm)` |  | Yes |

### Returns

`number(mm)`
Turn on units of measure (BREAKING CHANGE) (#6343) * Turn on uom checks Signed-off-by: Nick Cameron <nrc@ncameron.org> * Convert all lengths to mm for engine calls Signed-off-by: Nick Cameron <nrc@ncameron.org> --------- Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-04-23 10:58:35 +12:00			`---`
Add subtitle to docs and fix primitive type links (#6724) Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-05-07 10:33:23 +12:00			`title: "units::toMillimeters"`
More docs fixes (#6733) * Fix various docs errors around std module Signed-off-by: Nick Cameron <nrc@ncameron.org> * remove KCL from lang docs titles and move settings docs Signed-off-by: Nick Cameron <nrc@ncameron.org> * Include functions declared in Rust in module docs Signed-off-by: Nick Cameron <nrc@ncameron.org> --------- Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-05-08 08:26:56 +12:00			`subtitle: "Function in std::units"`
Turn on units of measure (BREAKING CHANGE) (#6343) * Turn on uom checks Signed-off-by: Nick Cameron <nrc@ncameron.org> * Convert all lengths to mm for engine calls Signed-off-by: Nick Cameron <nrc@ncameron.org> --------- Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-04-23 10:58:35 +12:00			`excerpt: "Convert a number to millimeters from its current units."`
			`layout: manual`
			`---`

			`Convert a number to millimeters from its current units.`

Some improvements to the boxed signatures in the docs (#6593) * Show a more reasonable name in function docs Signed-off-by: Nick Cameron <nrc@ncameron.org> * Fix buggy docs for union types Signed-off-by: Nick Cameron <nrc@ncameron.org> * Make types in the docs signatures into links Signed-off-by: Nick Cameron <nrc@ncameron.org> --------- Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-05-01 04:03:22 +12:00			```kcl
Docs improvements (#6615) Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-05-02 03:56:27 +12:00			`units::toMillimeters(@num: number(mm)): number(mm)`
Turn on units of measure (BREAKING CHANGE) (#6343) * Turn on uom checks Signed-off-by: Nick Cameron <nrc@ncameron.org> * Convert all lengths to mm for engine calls Signed-off-by: Nick Cameron <nrc@ncameron.org> --------- Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-04-23 10:58:35 +12:00			```

Add subtitle to docs and fix primitive type links (#6724) Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-05-07 10:33:23 +12:00

Turn on units of measure (BREAKING CHANGE) (#6343) * Turn on uom checks Signed-off-by: Nick Cameron <nrc@ncameron.org> * Convert all lengths to mm for engine calls Signed-off-by: Nick Cameron <nrc@ncameron.org> --------- Signed-off-by: Nick Cameron <nrc@ncameron.org> 2025-04-23 10:58:35 +12:00			`### Arguments`

			`\| Name \| Type \| Description \| Required \|`
			`\|----------\|------\|-------------\|----------\|`
			\| `num` \| `number(mm)` \| \| Yes \|

			`### Returns`

			`number(mm)`