Watched a few youtube videos explaining how to measure the correct chain link. Got it. Then found online chain length calculators. Makes sense too. But now I totally confused.

So, assuming I know my bike's chain stay...

• Do I measure the length on my bike or do I simply set the number of links exactly as recommended by calculators
• Also, this calculator sometimes comes up with odd number of links. Do I round up or down to make it even?

Thanks