How often have you wanted to retweet an awesome tweet and find that adding "RT @username" just won't fit in 140 characters?

Well, if you want your tweets to be retweet friendly, you need to subtract the length of the "retweet prefix" from the 140 character limit to know how long your tweet should be. It's a different length for everyone since it depends on the length of your Twitter username. So if you're like me and you're too lazy to do the math in your head, then just plug in your username below and hit the calculate button!