How long should you wait before you reply back to a girl. Should it be contingent to the same amount of time it took her to respond to you, a little shorter or a little longer?

Example: She replies 1hr later
-You reply also 1hr later?
-You reply 45mins later?
Or -You reply 1hr 15mins later?

How would you calibrate it?

It's 10 mins. but it's not about how much time you "should" wait. What you need to understand is why. You want to seem busy. Like you're doing something and you will get to her message when you get a chance. Here's what I do. For text, I'll take my phone out. Look at it. Go back to what I'm doing and when I finish I'll write back. Not only does 10 mins go by but it also lets you come up with a spontaneous reply. I would suggest you do the same thing with the internet POF/OKC. Remember there is no right or wrong answer.

I do want to add that you don't always have to wait ten mins. Switch it up. 10 here 10 there. Hell if you come up with a quick witty response just say it. I can't stress enough how many people on here OVER THINK the simplest of things.