Using fractions for input in the scale tool

2/3 is taken to be a request to make it be that size. If you try resizing a square it comes out with a diagonal of 2/3 units.

Yep, that is what I suggessted above. I usually do this when designing stair stringers. It never works if you just copy and paste the first rise/run convo…it always ends up creeping up…

By using a line with divisions we just let sketchup do the work to figure out that 1/64"

Agreed. However 1/3 is dimensionless and 1/3" is dimensional. I’m think that, if possible, that would be a good way to differentiate as inputs.

Hi, yes, I saw that. See my reply to eneroth3. Just as we can use 1, 1’, 1m to differentiate between units in the dimension box, would it be possible to implement 1/3, 1/3", 1/3’, 1/3m?

I do understand when you add a dimensionlees njmber it defaults to your default units, but it seems this would not be an unsurmountable obstacle.

How about 1/3p (for proportion) just like we have 3:12 for pitch, or 3h5m34s for degrees, etc…?

@DaveR, why withdraw your post? I was almost at the end reading it and was thinking of “Liking” it.
Phuf… gone. Why?

After posting it, I figured the OP wasn’t interested in a solution they could use now to do what they asked for. I think they really intend this as a feature request.

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Still, your solution is worth mentioning here for others. Just like the OP’s own solution to use the ‘Divide’ option on an edge and use the new endpoint as reference.
A feature request is quite valid, yes.

Hi, I used the “divide” solution, as I do often times. I had just never come across having to use it for scaling.

My intention was to find out if I was doing something wrong not being able to use proportional scailing…You are right it ended up being more like some musings and some sort of feature request… :thinking:

True. Usually SketchUp interprets numbers as lengths based on the Model Unit settings, but for Scale tool dimensionless values are already supported, so there shouldn’t be a clash.

Just be aware that if you try to use Imperial/US Customary units in the measurement box in a drawing set to metric units, you get very confused results even in the latest version of SU, especially with fractional inches.

See SU doesn't recognise fractional inches (e.g., 1/2") as an imperial measurement when units are mm

There are several past Feature Requests asking for the measurement box to accept arithmetic expressions. In general, it doesn’t. There are a few exceptions, which I can’t remember at the moment.

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A problem with that idea is that in all other cases you can leave off the units part. 6 in an inches document is the same as 6", and 10 in a metres document is the same as 10m. How would SketchUp know if you were leaving off the units or trying to do a scale fraction?

Perhaps one way would be /3. That is, you start to scale, type /3, and that would mean that you want the scale to be one third.

But say I wanted to scale the (any) selection to 2/3 in one go.
There must be a better composition than /3
I know, the following step could be to scale up with factor 2.

Until then I would isolate a selection together with a “dipstick” in a group. The dipstick would be a specific length to begin with. Say for scaling with factor 5/7… the length of the “dipstick” would be 7 units. Then the ‘Tape Measure’ tool would allow you to perfectly resize the group’s content to 5/7 the original size by measuring the “dipstick’s” length > type 5 units > anwer SketchUp’s question with “Yes” and [Enter].
I prefere to let SketchUp do the work.

There must be a well thought of intuitive combination of characters to allow as input straight into the ‘Measurements’ box to extend the use of the ‘Scale’ tool for simple fractions, as requested by the OP. A nice feature request.

How about x2/3?

Whether or not that might work in future, I don’t know.

But I and others on the forum I’ve seen use x as a shortcut for Xray view. It’s why in Move/Copy, I always use 3x (or 4x or however many copies I want, rather than x3 etc.)

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How about /1/3, so you can also do 2/3 and so on? using the forward slash would be highly intuitive

  • / ==> this indicates the incoming expression is to be used as proportional scailing
  • 1/3 ==> this is the proportion I want my model to be scaled by…

Or how about /2,3

  • / ==> indicates proportional scaling
  • 2 ==> indicates numerator
  • , ==> indicates the separation between numerator and denominator
  • 3 == indicates denominator

or 2:3
or :2,3

If you use /2/3 you could use /3/2 to increase the scale by 50%, /2/1 to double up, and so on.

In reality, scaling is always intuitively thought of (at least in Spanish) as an equal and proportional increase or decrease in the dimensions of an object - like we do when scaling models to paper-space, not as using an additive value to increase or decrease the object which, by the way, I think is awesome we can do in SketchUp.

I’ll stop now :slightly_smiling_face:

I was suggesting x2/3 because that’s consistent with making arrays. With an array you can type x4 to extend four more copies, or /4 to spread out four in between copies. With scale, x2/3 would multiple the existing scale by 2/3. /2/3 ought to multiply the scale by 1.5.

So, instead of using / as a special indicator of what you mean, it would be the normal divide indicator, as would x, only modifying the scale in this case.

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There is no need for a complicated “syntax” here. SketchUp could very well just parse 2/3. Since the Scale tool by default interprets the values as factors, not lengths, there is no ambiguity to 2/3".


An example of this would be, say, if you wanted to set construction lines either side of a central one. You know the overall dimension between outer lines. Let’s say it is 2789, an awkward one to divide in your head reliably. So instead, you type in 2789/2 (assuming mm is your default). That works.