Irregular Dimensions When Drawing Objects


I’ve been using SketchUp for roughly 2 years and have never had this issue crop up until recently. When drawing even the most simple objects, dimensions seem to alter themselves across the course of a project. When drawing an object up with a variety of different tools, I always type in the specific value to ensure this is exact. However, I’m finding that these values differ across a single line of an object, despite being drawn on a flat, even surface. I’ve attached images to illustrate this below. I’m designing with the units set at 0.0, however it’s then feeding back measurements of 0.0~, so I have to switch to 0.000000 to actually work out how much off this distance is. I also always use arrow keys to lock shapes I’m drawing on to specific planes.

This then has a knock on effect when continuing to draw/use the tape measure tool from various points on an object, meaning my overall shape is off the exact size I want by the 0.0000006 or some other annoying figure along those lines.

This is doing my head in and I can’t work out why it has only just cropped up as an issue when designing in SketchUp. Please would someone be able to advise why this may be happening and how I can sort this out ASAP!

Many thanks in advance,


Go to Window/Model info/units and untick Length snapping.

It is unticked currently, I’ve already tried this as a solution and created new projects to see if this would help, still to no avail!

Can you attach a model. Even just your standard template.

Sketchup_Dimensions_Test.skp (17.0 KB)

Thank you very much, appreciate you helping out mate!

I’m curious how you started this model. The endpoint closest to the origin isn’t actually at the origin.

If I move your geometry away I can draw at 0.0.0. So it’s hard to see where the error begins.

I just copied and pasted the object I was working on over to another document, so didn’t start drawing from the origin point. Does not drawing directly from the origin point potentially have an effect on dimensions like I’ve been struggling with?

Well, yes and no, the fact it is so close without being at 0.0.0 makes it suspicious.

There could be some hidden junk in your model that is throwing things of by a tiny amount which just runs through the model.
Hence asking to look at your template.
Open a blank model, turn on hidden geometry and hidden objects, tap ctrl a, or the mac equivalent for select all, and look in Entity info to see if there is anything there that shouldn’t be.

All seems fine on a blank document, could it be a specific object within one of my files which could be throwing everything off? I often will copy and paste specific items between documents, as I design board games which will often use the same components. If so, how do I go about identifying such component so this issue doesn’t persist going forward? Cheers for your assistance!

Sounds like you have some errors in the originals that you are bringing into new files.
I would check everything for proper alignment before using it.
The half circle in the model you attached is not aligned ‘on axis’. the straight edge isn’t following the green axis so if you use it as a starting point it will throw other things off.

This is what I see when looking at your model from underneath:

Also, what is the purpose of breaking up the edge (291. ___) into four segments? Why the extra short segment?

How do you go about seeing the 0.0.0 value like you are in your last screenshot? Would be super useful so I can continue to check my drawings going forwards. Going to have to start from scratch on this one it seems :frowning:

This is a curio, I suspect there is some kind of floating point issue here.
If I scale it up by 1000 it momentarily breaks, it doesn’t know what’s on axis or what isn’t and all the interfering freaked out, but after hovering over an endpoint all is revealed

Now I can only guess how this might happen, but as it is a small object I would wonder if
You’ve been drawing on a DWG import? and/or drawing this object a long way from the world origin (the axis)

Just use the text tool.

A lot of this may come from an obscure aspect of how SketchUp’s “clean up” operation works when a new point and an existing one are very close together. It presumes the existing point is the correct one, even if the new one is from an inference snap, and will move the new point to share the vertex with the existing point. This happens even if the new point is from an accurate inference snap (such as origin) and the existing point is a tiny amount imprecise.

Here’s another example: draw a line from the origin to 0.9999 in red direction. Now draw a line from (1.0, -1.0, 0) to (1.0, 1.0, 0). The new line will break at the red axis, as you would expect. But if you test its midpoint, you will find it is at (0.9999, 0, 0) even though that is not exactly on the new line you drew.

In this way, early imprecision in a model can propagate to contaminate things drawn later. This can particularly be an issue with models imported from other apps that don’t have this kind of clean up operation hence tolerate small imprecisions.


It isn’t just about new midpoints. Any existing endpoint has a attracting affect on new edges that pass within SketchUp’s tolerance when existing endpoint and new edge come together in the same drawing context.
Example: create a circle with many segments in a group’s environment. Position the “circle” group on (snap to) an existing long edge, somewhere between its endpoints. All is okay.
Once you explode the circle group it’s first two segments near te long edge remain but their endpoints distort the long edge.


True, it’s any pre-existing vertex that can magnetically draw in a new one. I just gave one example to demonstrate the issue.

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