Impression calculator based on online ads?

calculate impressions

[webtester01]

I'm working on a simple calculator on a site where given a number of sample size for an ad, click-thru rate, and confidence level, I want to estimate the number of impressions to serve.

I know, I can simply take the number of sample size a user enter, the click-thru rate a user enter, and divided them (i.e. 384 /.1% = 384,000). However, where does the confidence level and/or perhaps the survey completion rate (number of completes / number of clicks on the survey ad) fit into the formula to estimate the number of impressions?

[cgrantski]

Probably a search on "binary distribution confidence levels" will get you to the formulas you want. It's a binary distribution because people either click or don't click. You are absolutely right about the confidence level depending on the number of impressions.

I wish I had the right link for you, but I don't. If you find one, would you come back here and post it please? It's something that a lot of people could use once they discover the confidence concept.

[webtester01]

Do you know of an online calculator that has this?