Pixels to Points Conversion in Adobe InDesign CS4

An issue that usually comes up when wireframing in a program that is vector based such as Indesign or Illustrator is that you are really just guessing what size the fonts should be. This can create problems down the line since you can go much smaller on a vector based program than with pixels.

I have never really bothered with trying to figure it out completely but today I managed to do so and since I use InDesign almost exclusively (here’s why) I thought I might share this. Then again, it might be that I am the last person on earth to discover it.

It boils down to this formula:
Size in points = size in pixels / (body size in InDesign/body size in pixels)
eg.
Size in points = 10px / (500pt/1000px)

If this is new to you feel free to read on.

Where to find points as measurement in Indesign

1. Figure out what the width of your site will be. I use this grid calculator to do exactly that.
2. Once you have figured out your body width (let’s say 1000px), measure how wide your pages are in InDesign. This measurement should be in points and should be only the area in the body of your design. Best way to do this is to draw a square that you think it wide enough, you could also try and size it so you have nice round numbers. On an A4 page, 500pts work rather well.
3. Take the width of your working area, or body, for example 500pts, and divide it by the width of your site. In this example the number we get is 0.5
4. From now on, whenever you define a paragraph style that sits within your webpage in InDesign, divide the amount of pixels by the number just obtained. A font size of 10px would thus translate to a point size of 5 pt in InDesign.