How do I use the line height properly?

I would like to use the line height to reflect line spacing in a word or online text. The default value of line height is 0 pixels. I'd like to set it to something that resembles a line spacing of 1,5.

How can I use the line height for that purpose?

Simply try different values. Just be aware that the spacing will be different for different fonts. And it may not look the same on different devices.

If you want pixel-perfect results you need to use a sprite font.

Thank you for your answer. I think what works now is that I set the line height to fontsize * 1,5. It is checked by an accessibility professional right now (writing something in easy language requires a line height of x1,5, thats why I have to get it quite exactly right). It looks ok on the first glance and also works with different font sizes.