Imperial dimension – metric drawing

One of my colleagues noted that she wanted all her measurements to be in imperial when dimensioning for her client. The drawing had been drawn in metric mm.

Whilst there are ways to convert the drawing in its entirety into imperial and visa versa, there is very little information on temporarily change the units or dimension style.

So here is how to place an imperial dimension on a metric drawing.

First go to the dimension style manager (_DIMSTYLE) and then select your dimension that you will be starting with. In our office we have a dimension style for each scale the drawing will be printed at (we have not got to annotative objects yet…). So I started with 1:100.

Metric Dimstyle, Primary Units tab
Metric Dimstyle, Primary Units tab

Click on new and it will create a new style based on the 1:100 dimension style selected. I renamed the new style to 1:100 feet so its clear that it is a different style but has the scale of 1:100 and is in feet!

Then leave every other setting alone and go to the Primary Units section. Change the unit format to Architectural and the Precision to 0′-0″.

Then change the scale factor to 0.0393700787. This scales the mm in inches. It is the basically the conversion of 1mm to 1inch.

Imperial Dimension (for metric drawing), Primary Units tab
Imperial Dimension (for metric drawing), Primary Units tab

Save style and that’s it. You now have a dimension style that outputs feet and inches from a metric drawing. Even better you can have both metric dimensions and imperial on the same drawing with this method.

Advanced dimensioning

This tutorial follows on from the dimension style basics one.

One of my colleagues was wanting dimensions that show a half (.5) after the measurement for when setting out brick diemsnions but not wanting the dimenions to have point something (e.g. 0.34 or .0) after them. And another wanted km dimensions. I will explain how to do both of these here.

Trailing Zeros

So lets alter the new dimstyle created in that post, called Adams – 1_100.

If we go to the primary units section,  change the precision to 0.0 and the round off to 0.5, this will allow the dimension to only present halves of numbers and not other fractions. All dimensions will now look like this: 1000.0 or 1020.5.

In order to remove the .0 for dimensions that do not require it, check the trailing zero supression box and now dimensions will look like this: 1000 or 1020.5.

km from mm

For example if you draw in mm and want to present the dimensions in km, again go to the primary units tab and add km as a suffix and change the scaling to 0.000001. This is the conversion factor from mm to km. Now the dimensions will only display km. As the precision is not required at that scale I would change the precision to 0.0 and add zero supression. 

I would suggest creating a new dimension style when altering the dimension this drastically.

Dimension style basics

This tutorial follows on from the text style one.

So once you have created you default text style (NOT STANDARD), click on the annotation panel again and go to the dimension style editor.

Default dimension style
Default dimension style

You will get a similar box to the text style dialog, albeit the preview has moved from bottom left to the centre! However the principals are the same. Again, please do not use standard.

So, click on the new and you will get a box, give the dimension a name. Again, similar to the text style, give it a name that reflects where it came from and what it does, e.g. ‘company name – 1:100’ (metric), or ‘company name – 1/8″=1’-0″ ‘ for imperial.

Create new dimension style
Create new dimension style

You should note that AutoDesk being totally dumb have excluded pretty much every symbol that describes an imperial or metric scale. So the above two examples have to be re-written to make sense but won’t actually follow standard notation.
– company name – 1_100 (metric)
– company name – 1_8_-_1-0 (imperial)

Unsupported Characters
Unsupported Characters

Again, this is only a suggestion of how to put it together, just keep it simple to allow others to get what the style is to be used for!

I am going to use metric for this example, however the principals will be the same for imperial.

So once you have entered the name, you will be presented with the (rather complex) dimension style editor box. This is a very powerful set of rules that can present dimensions however you want, some of the features are:
– rounding of dimensions
– scaling to other units, e.g. if you draw in mm, the dimstyle can display km!
– zero supression at both end and beginning
– location of text
– style of leaders
– style of lines and more!

The first tab to the left is lines, we will come back to that one. First lets set up the text.


Text tab, dimension style
Text tab, dimension style

Change the text to the text style you created, this hopefully won’t grey out the text height in the dimension style. If you altered the text style height to anything other than 0, you caa change the height in this box, I usually use 2.

I like my dimension text to be centred and aligned to the dimension line.

When looking at the numbers on all the the tabs, they will be point something. This is because the defaults are set up for imperial. If in doubt change these to 1 for metric. Sometimes a 0.5 or 2 might be more suitable. A little playing with the numbers after creation will get the dimension style looking as you want it.


Line tab, dimension style
Line tab, dimension style

After the text is setup, lets look at lines. The default for this page is everything set by block. If you, like I, draw using layers, then change all “ByBlock” to “ByLayer”.

I also like to make my lines a little fancy by changing the extension lines to a grey (that plots light in colour) and to “hidden” to provide an unintrusive dashed line back to the origin points.

Don’t forget to change the spacings to 1.

Symbols and arrows

Symbols and arrows tab
Symbols and arrows tab

Most of the settings on this page are personal preference. I prefer architectural ticks on my dimensions and a little arrow on my leaders.

I found from experince that 1.5 for arrow size seems to work quite well, center marks at 1 and a break size of 2.


Fit Tab
Fit Tab

This one is where the overall scale (if not annotative) is set. Once one dimension style is set up, it can be copied at the “use overall scale” section changed to suit the scale. e.g. here we are going to change the overall scale to 100 for a 1:100 dimension style. If 1:50 change this to 50.

The rest of the options in this section I leave at default.

You will notice that once the overall scale is changed the preview might go wild. If it does, just close and click your style and click modify.

Primary Units

Primary units tab
Primary units tab

This is where the precision and rounding is undertaken for the dimension style. You can also add suffix to the dimension.

Here I have altered the precision to 0.0 and changed the round off to 0.5 as precision greater than this is not normally required at 1:100. In fact you could change the precision to 0 and round off to 1 or even 5. Round off takes the dimension of say 3549.23435 (if measured using DISTANCE) and displays a more friendly number in the dimension. So if the round off was 5 and the precision 0, the dimension would read 3550.

Alternate Units and Tolerances

These are not generally used in architecture and for this tutorial the defaults will be left on these two tabs.