Can I change the measurement unit of a Draw.io diagram? By default, all the measurements are in pt except the page size (in mm).

I'd like to enter the shape dimensions in mm or inch instead of pt.

Is it possible at all?


Since October 2019, draw.io is able to work with millimeters. Just select View > Units > Millimeters from the draw.io menu.

  • Yes it works now. After switching to mm I had to change the grid size to make it work.
    – Heiner
    Jul 6 '20 at 9:49

Nope.. That won't be possible. Convert mm/inch to pt and work with it. It's tedious, but also the only way 1mm=2.83465pt & 1inch=72pt

  • 1
    A nice workaround? It is not nice. And I would not call it a workaround. As it is the obvious way to work if this feature is not available.
    – Heiner
    Jun 14 '17 at 7:10
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    As of posting this comment, 1 inch in draw.io is equal to 100 points. Convention dictates that (1 in == 72 pt), but the application doesn't seem to be designed that way.
    – kccricket
    Oct 26 '17 at 15:13
  • By just trying things, I was able to get what appear to be inch-sized major (quarter-inch sized minor) ticks by setting grid to 25 pts. (This bears no obvious relation to 72 pt / in. - but I'm curious if there is one.)
    – Dav Clark
    Dec 26 '18 at 20:22
  • As of this writing I find that 120 pts is 1 inch. I set the grid to 15 pts to get a 1/8th inch grid (which bears no relation ship to the Ruler markings, which seem to have a tick every 10 points). I did a 90 point circle bisected by a line and found the diameter, when printed to be 3/4 inch -- exctly as I intended. My print job was at 100% scaling. Page size set to US letter in drawio and for printer.
    – Dave Hein
    Jan 31 '21 at 22:03

I can confirm the comment/answer by @kccricket still works.

1 inch in draw.io is equal to 100 points

You can simply divide by 100 any pt values to get inch.

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    Experiment. I found that 120 pts seem to map to 1 inch. There is zero documentation about this. I've no idea why some folks are finding 1 inch = 72 pts, 1 inch = 100 pts, and (myself) 1 inch = 120 pts.
    – Dave Hein
    Jan 31 '21 at 22:05

Unfortunately imperial measurements don't conform to 100ths of an inch. You can't effectively use this program to diagram things like architectural details that require dimensioning at 1/16th inch resolution for example because the grid only accepts whole integers. The best you can do is 1/4" (25/100ths) which is useless.

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