Code for fixed line break size?

What is the code for line breaks (<br>) of a "fixed" size, such that if a browser's font size is increased/decreased from the top menu bar, the line breaks will still stay the same size?

In other words, if <style>.fixedfont5{font-size:##px}</style> sets a fixed font size, what would be the equivalent for a fixed line break size?

I think this will do it:

.fixedfont5 {
font-size:##px;
line-height:##px;
}

If so, maybe a Mod should move this thread?

<style>
br {font-size:50%}
</style>

Or just apply it to the br tag directly with:

<br class="fixedfont5">

Thanks so much COBOLdinosaur and Graeme Hackston. I really really appreciate your expert assistance!!! I just discovered this form and you guys make it a real pleasure. By the way, <br class="fixedfont"> was the perfect fix.