Scale factoring equation?

hello

I am trying to understand how math works for scale factoring to specfiy a smaller or larger inserted object. Working with a door. I want to set the door at 3'. To do so I need an X scale factor for 12.

The factors for factional inch scale is derived by multpying the denominator of the scale by 12. Then dividing by the numerator.

Example. If the scale for 1/4" = 1',0" is ( 4x 12) / 1 or 48/1.

Not sure if these figures below have anything to do with the scale Factoring problem at hand. But.

For 3/16" = 1'-0" scale the operation is (16 x 12) / =3, or 64.

For whole foot scales like 1" = 10', mutlpe the feet side of th equation by 12.

There's alot to look at here so if anybody can please brake down the above scale for factoring. Thanks.

What is the size of the door which you want to scale? The scale factor you are looking for will be the relationship between the original size and the new size. If the door was 2' and you now want it to be 3', then the scale factor will be the inverse of 2/3, which =3/2 or 1.5. You can enter it into your scale factor prompt on the commandline either way, as a fraction, or as a decimal. That is nice because it precludes the need to do a decimal conversion of a strange fraction, say 57/129.

If you are trying to scale a door which is 3' to 12', then you want the inverse of 3/12, which is 12/3 = 4.

If you can draw your block so that it is one unit in size, then you can insert it at the size required without going into complicated maths

But with doors, for example, the size of the jambs and thickness of the door are constant, and it is only the door length that scales.