# Thread: Converting metric to inches

1. ## Converting metric to inches

Registered forum members do not see this ad.

I have a drawing that was drawn in metric and scaled down to somewhere between 1/32 -1/64.

How do I convert the drawing to inches?
And
How do I convert it to 1:1 scale?

I need to insert a few blocks and they were drawn in true 1:1 scale in inches.

2. First off, remember that AutoCad draws in "units" and doesn't have any specific measuring system attached to it. A line 4 units long can represent four centimeters, four inches, four furlongs, four kilometers, or four miles.

You will have to check the length of a known entity and use the scaling function (also referred to in some texts as "size multiplier") to "convert" to the proper size you want. This applies to both the metric/inch conversion (1 inch = 25.400 mm) and the fractonal size of your drawing; you may have to do two scaling operations.

3. OK,
So how do I find out what 1 unit is equal to in a drawing?
And then..
How do I change it?

Example: If 1 unit is equal to some metric value, say centimeter, how do I change it to the inch equivalent of .3937?
And then
How do I scale the drawing up/down to 1 unit = to 1 inch?

I also need the dimension to reflect inches.

.

4. At the command prompt, type SCALE.
Autocad will prompt you to pick entities; either click on them or window them.
Hit ENTER
Acad will prompt you for a base point (around which to scale); click the desired 'point of reference'.
Acad will prompt you for a scale factor; type in the multiiplier you wish to use. If the drawing is millimeters and you wish inches, type in 1/25.4. Don't use .03937; it isn't accurate enough.

As for the other scaling which was done: was it only done in the hard-copy plot? If so, the Model Space drawing will be 1 to 1. If the Model Space drawing is also scaled (down I think you said?) you will have to measure an actual object for itsw length, then scale the entire drawing by whatever fraction (decimal) to reach one-to-one.

5. Thanks Vince.
I'll try that and let you know how it works out for me.

6. Hi zimtok

Just a very quick and short note

“Welcome”

There’s an old saying “you only get out what you put in” and that is very true of this melting pot of advice and ideas where you can be sure of a friendly helping hand along life’s long journey of AutoCAD.

But we all would like to know more so please don’t be shy and introduce yourself to us all.

Now to try and help you out. With 2008 if you open a drawing in model space and right click / options you can see what units the drawing was drawn in the first place, well I think you can.

Once again welcome

7. Originally Posted by Bespoke Cabinet Maker
Now to try and help you out. With 2008 if you open a drawing in model space and right click / options you can see what units the drawing was drawn in the first place, well I think you can.
'fraid not. That is set by the user to ensure unitless blocks are scaled correctly. It has nothing to do with the units used at drawing time. Only under exceptional circumstances do I use anything other than UNITLESS.
That particular setting came in around about 2006 and it has only been added to the options screen on 2008 (possibly 2007)

8. vince,
I tried to type in the 1/25.4 and it would not accept it.

9. I think that one unit is equel to 1 meter in this drawing I have.

1 meter is equal to 39.37 inches.

So I scaled all the objects up so that one unit equals 39.37
That seems to be very close.

My imported items seem to be correct in size.

Is there a more acurate value to use in place of 39.37?

.

10. Registered forum members do not see this ad.

We had this problem once! Are there dimensions on the drawing? Do you know what the conversion from metric to Arch. is? Do a distance on a something you know what its length is suppose to be. Let's say it is a dimension that says 10'-0" but the distance you get is 3'-0". So you have to scale up by 3.333333. (divide 10 by 3) With your drawing being in metric it may be hard to get everything to a tru arch scale, but this may be a start.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts