Time weighted rate of return and IRR (internal rate of return) are identical where there have not been any contributions or distributions from a portfolio during the measurement period.

TWR is not the simplest calculation, but understanding how it works is helpful. We’ll break it down and provide examples to show what TWR may look like in action.

Today’s Google Doodle celebrates clockmaker John Harrison, whose efforts to calculate longitude helped people figure out their place in the world — literally.