Measuring a Distance in Hammer

So lets say I decently tall ceiling but I want a concentrated light source beaming down onto the floor.

I use light_spot and I need to change the max distance, how do I measure the distance from the light entity to the floor?

Or, how do I measure any particular distance in Hammer?

Thanks!

It’s in units. Make a bar x units long as a measurement

I think if you select two objects it shows the distance in the bottom right.

Make a box with the selection tool

I found a useful tool online and I forgot where to find it :saddowns: so I uploaded it to garrysmod.org
http://www.garrysmod.org/downloads/?a=view&id=84933
I know it says its not safe, you can just wait until it gets checked before you try downloading it.
It measures meters, feet, etc.

http://img163.imageshack.us/img163/690/sdkmeasure.jpg

Does this help? I used the selection tool, just as Nerdeboy recommends.