# About the distance unit between two points when markup by line

**URL:** https://discourse.slicer.org/t/about-the-distance-unit-between-two-points-when-markup-by-line/29041
**Category:** Development
**Tags:** markups
**Created:** [April 21, 2023, 9:30am UTC](https://discourse.slicer.org/t/about-the-distance-unit-between-two-points-when-markup-by-line/29041 "2023-04-21T09:30:09Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![dbtruong](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dbtruong/32/65581_2.png) [@dbtruong](https://discourse.slicer.org/u/dbtruong)
#### Post date: [April 21, 2023, 9:30am UTC](https://discourse.slicer.org/t/about-the-distance-unit-between-two-points-when-markup-by-line/29041/1 "2023-04-21T09:30:10Z")

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Why the distance between two points is millimeter?

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### Author: ![chir.set](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/chir.set/32/66982_2.png) [@chir.set](https://discourse.slicer.org/u/chir.set)
#### Post date: [April 21, 2023, 9:48am UTC](https://discourse.slicer.org/t/about-the-distance-unit-between-two-points-when-markup-by-line/29041/2 "2023-04-21T09:48:09Z")

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Because there needs a default unit.

You may change to another unit in Application settings / Units / Advanced.

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### Author: ![dbtruong](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dbtruong/32/65581_2.png) [@dbtruong](https://discourse.slicer.org/u/dbtruong)
#### Post date: [April 22, 2023, 9:10am UTC](https://discourse.slicer.org/t/about-the-distance-unit-between-two-points-when-markup-by-line/29041/3 "2023-04-22T09:10:08Z")

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The distance unit between two points in world coordinates is a millimeter, isn’t it? Can you explain that?