Geek Stuff How to calculate an internal rate of return (IRR), and when not to use it | Experiments in Finance March 4, 2008 Jack How to calculate an internal rate of return (IRR), and when not to use it | Experiments in Finance Very Interesting. Share this:Share Click to share on Facebook (Opens in new window) Facebook Click to print (Opens in new window) Print Click to email a link to a friend (Opens in new window) Email Click to share on Pocket (Opens in new window) Pocket