Say in list view you have a field 3 inches wide, is there a simple way or a trick to determine the max characters it will hold while in layout mode to create a calculation field using the left function?

I realize this is font and font size dependant.

Yes to get what I needed I typed in some test data of 1 2 3 4 5...etc and counted until it wrapped. But to do that for each field...you get the picture I assume. But I have a layout where the field could contain a few characters up to a really long input. Another example could be shortening a URL field for display purposes vs a button using the actual input field the button uses to go to that specific URL.

When a line wraps looks messy with the next lines text trying to show if you have another field right below it.

TIA

It's not only 'font and font size dependant' - unless you are using a mono-spaced font, such as Courrier, it is also content-dependent.

The next line of text should not show at all, if the field's height is matched to the font size. In any case, you can increase the line spacing in Format > Text ... > Paragraph...

Yes I understand 35 "l"'s is a lot narrower then 35 "O"'s. The font and the field size I am using is based on a pdf I got that was centered around a rapid deployment of FM. I am at work and the pdf is at home so I don't have the name of the project or doc name with me. I know the recommended font was Verdana 11pt (middle). Off the top of my head I think the field height that doc said to use was .265 of an inch for Verdana 11 pt.

Your post makes it sound like field height to font size ratios are stated in a chart or a book or discoverable. Granted a newbee and still reading, testing, etc and have not seem a reference to a font size to field height mentioned in anything I have read yet. Is this information stated somewhere. Primary source of reading-reference is 8.5 Bible and forums like this.

TIA

Your post makes it sound like field height to font size ratios are stated in a chart or a book

No, all I meant was that Filemaker tries to adjust it for you. For example, if you turn engraving on, then change the field's width by dragging, the height will be automatically increased by 2 pixels. IOW, you need to work on it in order to screw it up.