Saturday, August 26, 2023

How to Calculate Scale Factor for Scaling Objects in AutoCAD

 If you are scaling an object in AutoCAD using the "SCALE" command, you will be prompted to enter scale factor. In as much as the scale factor could be entered on the fly, it would be proper to know the exact value that needed to be entered to scale an object in a precise manner.


To calculate the 'Scale Factor', lets consider the points P1 and P2 seen above. The distance expected is 407.97m, but when measured using the measuring tool the measured distance was 161.64m.

So, the 'Scale Factor' will be Expected distance ÷ Measured distance. That is: 407.97/161.64 = 2.523942093541203

Now select the whole drawing and perform the scaling using the 'Scale Factor' calculated above. The distances will be scaled properly and when measured using the measuring tool, it will return the correct expected distance.

Note: For stubborn objects such as 'Rotated Dimensions', the 'Scale Factor' above will not work as expected. A work around is to create a new dimension style and set the 'Scale Factor' to 1/'Scale Factor'. That is 1/2.523942093541203 in the case above.

That is it!

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