Hi, I have a .dxf file that I want to measure each component, but I have my LightBurn set to mm while this .dxf file is designed I guess in inches.
IF there was a little ruller icon at the top icon bar where each time I clicked on it and it would change to the next type of dimensioning I see on the screen, I think I would see the dimensions I’m looking for in the little display windows to help me edit components in the .dxf file.
Did you try this?
The little mm button over on the right switches the displayed units between mm and inch:
Close enough? 
Bonus: You can specify the numeric value units if you want to nudge something over by a fraction of an inch when you’re in metric.
Double bonus: Equations!
If you take inches and want to convert to Milometers just multiply by 25.4, to convert the other way you divide by 25.4.
I’ve used this method for years.
You can draw your own ruler and store it in the art library. Pop it into your work anytime you need it.
Lots of skins on that (ruler) cat. Pick the one that works for you.
What a pain. In grade school science class they told us we’d switch to metric relatively quickly. However it hasn’t. Basing a measurement on a persons (the kings) foot and dividing it by 12 is pretty nuts.
Some fields in Lightburn will allow the computations in the field – this is simply multiplying and dividing by 2.
Ha!
In my shop I work with thousandth of an inch (milling, lathe although the DROs can flip back and fourth) ounces and CC (paint, Cerakote)
In the laser room its MM
In the reloading room back to thousandths of an inch but weight is in grains (7000th of a Lb) and volume is CCs. Blackpowder it is "volume equivalent " of grains.
In cad I still use feet and inches. But also MM or thousandths. Depending on the project.
Ill be long dead before there is a standardized measurement system!
Edit forgot about feet and inches on the table saw and other building materials.
Or even overriding the field units. In a 250mm field, you can enter 10.5" and it will respond with the equivalent 266.700mm. I often use 11.95" to set the T1 boundary for my 12"x12" Baltic plywood.
Hi, I know how to measure, but I want to change the units of measurement from mm to inches to mils etc.
Hi, Thanks! That is exactly what I was looking for!
I’d just like to be able to measure from point A to point B without creating an extra “feature” todo it.
The Measure tool does that:
In addition to what @ednisley offers, you can use the ‘Draw Lines’ (Pen) tool to measure from point A to B. Click at the start (point A), then drag to point B and look at the bottom information section for the distance. 
