[gojomo]

Nice tool!

Rather than providing one exit value, a graph over a range could be helpful, to illustrate key thresholds, like the slope-change introduced by preferences or the exit values needed to provide the founders/VCs a particular return.

Also, adding an optional 'months to exit' would allow displaying the effective internal rates-of-return for a given exit value.

[rabbitonrails]

There's also http://preferredreturn.com/calculator that has the graphing you describe and the ability to add multiple rounds. However, the FF one has a better interface for convertible debt & early stage.