Skip to main content
twinbrush
Inspiring
August 23, 2018
Question

Object dimensions are wrong/changing

  • August 23, 2018
  • 7 replies
  • 9927 views

Anybody else having 'issues' with the dimensions of objects being inaccurate in illustrator?

I've set up a document (CMKY and 50mm x 50mm artboard). Snap to pixel is off.

When I draw a rectangle of 50mm x 50mm everything seems good, but when I select the object again the dimensions actually read as 50.003mm. I can change the dimensions either in the control bar at the top, or the transform panel and everything seems accurate, but again if you deselect and re-select the object, the dimensions have again altered to this slightly off measurement.

I've heard some people say that Illustrator uses points and mm / inches etc get converted to points and some 'rounding up or down' occurs, causing this inaccuracy. Granted that kind of minuscule change is barely going to be noticeable, but when accuracy is important it seems illogical to round anything up or down. If units are set to mm, then Illustrator use mm to measure and set and calculate dimensions no?

I've reset preferences, restarted Illustrator (and my workstation) but still happening. Its another example of me constantly finding Illustrators accuracy absolutely awful. Kind of defies the purpose of entering exact values if they are going to be altered?

Rian

    7 replies

    Participant
    May 26, 2025

    make the box as a fill and remove stroke. it will show you 50mm x 50mm. But when you again add the stroke the measurement will increase. So its an issue in Illustrator

    Monika Gause
    Community Expert
    Community Expert
    May 26, 2025
    quote

    make the box as a fill and remove stroke. it will show you 50mm x 50mm. But when you again add the stroke the measurement will increase. So its an issue in Illustrator


    By @Moiz Hussain

     

    Turn off "Use Preview Bounds" in the preferences or the transform panel.

    Participant
    May 26, 2025

    Thank you very much

    Participant
    May 4, 2022

    It's happening to me as well.

    In fact, just now I have an artboard open in inches.

    I drew a square, locked its proportions and told itto make it 100 cm (because it always converted it for you).

    Low and behold, Illustrator thought it equaled 37". 

    So I changed the rulers to CM, drew a 100 x100 cm square and then it knew it was 39.97".

     

    The other day I fought with the program because it would NOT allow me to keep boxes the size I wanted.

    If I typed 5" x 6" it would convert the box to 4.897" x 5.696" etc.

    • I tried unchecking scaling corners, strokes ... etc.

    • I tried resetting preferences etc.

    Truth is, I'm going to have to start sending Adobe bills for labels we buy if they playing these stupid games because labels at the size I work with, those micro measurements are a LOT!

     

     See video.

    Anshul_Saini
    Community Manager
    Community Manager
    May 5, 2022

    Hi @GabrielHAZE,

     

    Sorry to hear about the issue you are facing. I checked your video, and it seems the "scale width & height proportionally" is checked.


    Disable it and enter the dimensions & check if you are getting perfect values as you intended or not.

     

    I will be looking forward to your response.

     

    Thanks & Regards,

    Anshul Saini

    SIMS SOLUTIONS
    Participating Frequently
    November 15, 2022

    Your screendump is 144 ppi, what resolution do you export? To get the same quality use 2X in export for screens.


    I usually use 300 but want do you mean on 2 times..."To get the same quality use 2X in export for screens."

    I thought maybe it was a MAC thing but I tried on a PC too and it looks the same. I also read it is a Chrome thing but I have tried on Safari and Bing. If it is a user error I am just dumbfounded. As I mentioned before the print quality of these graphics is fine and the same images are used on a website and they are fine too.

    Look at how bad this is when you click on the link.
    https://www.alignable.com/fort-worth-tx/forum/8402906-1668470697
    [https://pictures.alignable.com/eyJidWNrZXQiOiJhbGlnbmFibGV3ZWItcHJvZHVjdGlvbiIsImtleSI6ImRpc2N1c3Npb25zL3BpY3R1cmVzL29yaWdpbmFsLzEzOTE3MjcvU2NyZWVuUHJpbnRQb3N0Tm92MjAyMi5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjEyMDAsImhlaWdodCI6NjMwfX19]<>
    Avoid Repairs, Back Taxes, Realestate..., Fort Worth TX - Alignable<>
    Avoid Repairs, Back Taxes, Realestate commission or worse foreclosure. Get a fair value. Look at our reviews to see what are clients are saying about Kathy...
    www.alignable.com
    this one is bad too
    https://posts.gle/Nz21hUDgbH2FruVQA

    The website looks fine
    https://www.kathybuyshouses.net/
    [https://kathybuyshouses.net/buyhouses/cash-house.jpg]<>
    Buy my house, Sell my house Arlington, Haltom City, White Settlement<>
    Kathy Buys Houses will Buy any home, pay all the closing cost and no repairs are necessary. We Buy Houses in Tarrant County, specifically Fort Worth, Arlington, Haltom City, White Settlement, Hurst and Bedford.
    www.kathybuyshouses.net
    Researching on Google many people are mentioning the same so I am just trying to figure it out.

    https://support.google.com/news/publisher-center/thread/160814939/featured-images-are-showing-blurry-in-google-news-feed?hl=en
    Featured Images are showing blurry in google news feed - Google Publisher Center Community<>
    name=
    support.google.com
    there is much on this topic if you look. Please advice

    Melissa Sims,
    personal details removed by moderator

    Legend
    August 23, 2018

    Illustrator is not going to change its calculations to use the selected unit. That is for display purposes. So the units you type will be converted to whatever Illustrator uses internally. This is not a matter of deliberate rounding, but a consequence of that choice. The alternative would be worse.

    We don't know what Illustrator uses to calculate, but let's imagine it is the same as older versions of Acrobat, which was a type called "ASFixed". In this we store numbers as 1/65536 points. Whole numbers of points and inches would be stored exactly. This is just an exercise.

    In this, 50mm is stored as 50 * 25.4 / 72 * 65536. This is approximately 1,155,982.222222222 so it would have to be stored as 1,155,982 or 1,155,983. 

    1,155,982 converted back to mm is approx 49.99999038816437 mm.

    1,155,983 converted back to mm is approx 50.0000336414247 mm.

    So rounding will happen. People agonize over seeing small changes far after the decimal point without considering how small the difference actually is. Sometimes they demand the mathematically impossible too.

    twinbrush
    twinbrushAuthor
    Inspiring
    August 23, 2018

    I know the alteration is minuscule, and I have no idea why or how the calculation is needed...nor do I need to I suppose. It just seems necessary to me to do additional calculations, units of measurements should be the unit of measurement...but hey, I'm not a programmer

    Ton Frederiks
    Community Expert
    Community Expert
    August 23, 2018

    Do you have a (tiny) stroke around the rectangle?

    twinbrush
    twinbrushAuthor
    Inspiring
    August 23, 2018

    Nope, no stroke, just a solid fill of 0 0 0 100

    Jacob Bugge
    Community Expert
    Community Expert
    August 23, 2018

    Rian,

    Is it also happening if the Artboard and rectangle have the corners at whole X and Y values (especially 0,0)?

    0.003 mm ~ 0.001 pt, so a rather small deviation, more visually than practically disturbing, less than the bulging of a 10 pt circle.

    twinbrush
    twinbrushAuthor
    Inspiring
    August 23, 2018

    Yea the artboard x and y are 0 whole values. Its definitely such a small deviation that I doubt it would ever be noticed...just a pet peeve I guess, if as it seems, its just an internal calculation made by Illustrator

    ceyhun_akgun
    Legend
    August 23, 2018

    You can use the "Use Preview Boundaries" option in the Preferences panel.

    Graphic Designer Educator / PrePress Consultant
    twinbrush
    twinbrushAuthor
    Inspiring
    August 23, 2018

    Sorry if this sound silly, but are you saying that turning 'use preview boundaries' off is providing you with more accurate dimension read outs?

    ceyhun_akgun
    Legend
    August 23, 2018

    Can be used without marking Use Preview Bounds. If marked, it calculates the line thicknesses together with the width value.

    Graphic Designer Educator / PrePress Consultant
    Monika Gause
    Community Expert
    Community Expert
    August 23, 2018

    Which dimensions are off?

    Rectangle or Bounding box?