# Inches to metric



## Harry Briels

I would like to replace all usage in LR of inches to cm's but can not find a way for doing so.
If I e.g. select a image size it show sizes in inches. I prefer cm's
Thanks for helping


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## Hal P Anderson

The only place I know of that LR references inches is on Export, and you're given the choice of inches or centimetres:




I couldn't show it in one screenshot but you can specify pixels per cm in the other, marked dropdown.

Is this what you needed to know?

Hal


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## Jim Wilde

Hal, I'm guessing the issue may be in the Print module where at first glance selecting a print size was only in inches (e.g. 4x6). But on second glance I see the option to change the Ruler Units to a variety of choices, one of which is centimeters. When that option is selected the print sizes change accordingly, see screenshots:

 

The only things that don't change are the canned Print Templates that are in inches.


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## b_gossweiler

Also, you have to be aware that professional printing systems are still producing their prints in the imperial system, even in countries using the metric system (i.e. a "13x18" print actually is a 5x7"). So for reasons of resampling, it is advisable to specify the export size in inches if sent to a printing service.

Beat


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## Harry Briels

I am looking for a method to change all uses of inches in LR in to metric (cm's, mm's) not just in export or in print.
I am not interested in image sizes like 4" x 6" but in the metric equivalent of 10 x 15 cm because this is what we use over here in Europe.
Now I have to look up the cm-values of "sizes in inch" in a table which is kind of primitive.
So my question remains how do I replace in LR all inches into mm's?
Thank you for helping me out!
Harry


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## Jim Wilde

Muizen said:


> I am looking for a method to change all uses of inches in LR in to metric (cm's, mm's) not just in export or in print.



Apart from Export or Print, where else in Lightroom are you seeing dimensions in inches?


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## Harry Briels

TNG said:


> Apart from Export or Print, where else in Lightroom are you seeing dimensions in inches?



As an example in e.g. in "Develop mode, crop & straighten, original" all sizes are just in inches. 
This is not acceptable since there will be users who want to be able to replace these by metric image formats.
I am not going to look for other applications of inches versus metric but there will be more.


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## Jim Wilde

No, I'm afraid you're wrong. Crop 'sizes' are in fact nothing more than ratios, and as such they have no more relevance to 'inches' as they do to 'centimetres' or 'millimetres' or 'pixels'. You crop to a ratio (if the ratio is important to you), then when you export or print you can apply a real unit attribute. So using a 6:4 crop ratio would allow you to:

Export a file with pixel dimensions of 1200x800
Print a 6x4 inch picture
Print x 12x8 centimetre picture
*And it would allow you to print a 15x10 centimetre picture, because its the same ratio.*
In fact, given that 6:4 and 15:10 are the same ratio as 3:2, which is the ratio used by the majority of digital cameras, you could simply crop using the 'original' aspect ratio and not have to bother choosing one of the custom ratios.

You can also create your own crop ratios if the ones supplied with Lightroom don't suit. For example I routinely export some of my pictures for a couple of digital photo frames, the screen resolution of which is 1024x640 pixels.....so I have setup a custom crop ratio of 16x10 (same ratio as 1024x640) which I use on these pictures. Then when I export I resize using 'Long Edge' of 1024 pixels and the resulting exported files fill the frame fully on the photo frame.

You have to stop thinking in terms of imperial or metric measurements when you see those crop ratios....yes the supplied ones may have their roots in the standard print dimensions in inches, but they don't only have to be seen that way. They are ratios, not actual measurements.

And I do believe that the ONLY places in Lightroom where the ability to choose a measurement unit is needed is in the Export and Print Modules, and as we have already explained you DO have the ability to use metric rather than imperial measures in both those places.

I hope this has clarified things for you....


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## Harry Briels

Thank you Jim for your extensive reply and suggestions.
I will no longer be looking for metric in LR!
Harry


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## Jim Wilde

That's good to hear, Harry.


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## songjack

When I go to page setup while in Print Module I am in mm and not inches...how do I get it back to inches???  I have looked all over...please help asap thanks!!


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## b_gossweiler

Welcome to the forums, songjack 

Right click into the ruler and choose ...

Beat


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## songjack

I'm on a Mac, how do I do that?  thanks Bgoss


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## b_gossweiler

Control-Click, I think?

Beat


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## songjack

On what ruler?  where exactly.....thanks again


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## songjack

That's not where the issue is.  Control click worked for that.  I need to change from mm to inches in the page setup window thanks


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## b_gossweiler

Change the ruler to inches, and your layout options will also change to inches:


Beat


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## songjack

Anyone please help with this question.  Cannot get back to inches from MM in page setup thanks


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## b_gossweiler

Please post a screen shot of where you see metric and want to get to inches.

Beat


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## songjack

here it is:


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## b_gossweiler

OK, I see now that you're talking about the page setup, which is part of the printer driver's dialogs, not LR's. 

As I'm not a Mac user, I can't help you on that one, but I'm sure somebody will chime in soon.

Beat


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## clee01l

b_gossweiler said:


> OK, I see now that you're talking about the page setup, which is part of the printer driver's dialogs, not LR's.
> 
> As I'm not a Mac user, I can't help you on that one, but I'm sure somebody will chime in soon.
> 
> Beat


This is not (AFAIK) a print driver dialog for OSX. Page setup is a menu item on the main menu in the Print module.  I think your problem is that you have OSX system preferences set to metric.  Open your OSX System Preferences from the Dock  Choose "Language & Text" to open that dialog. Then  on the "Formats" tab set the "Measurement units" field to "US"  instead of "Metric".


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