Cap Table Simulator

An interactive cap table simulator to help answer the eternal question: what will this financing do to my ownership?

Cap Table Simulator

Almost exactly two years ago, I wrote a post about helping friends navigate the eternal “what will this financing do to my ownership?” question. Two years later, it’s still fundraising season (yes, it’s still always fundraising season), and while the original spreadsheet was good, it’s time for something better.

An interactive simulator!

The cap table simulator in action

What does it do?

With this simulator, you can:

  • Add Common Stock or Option Grants
  • Add Convertible Notes or SAFEs
  • Add Equity rounds

You can layer as many rounds as you’d like, with one or multiple investors per round.

The simulator will take care of:

  • Automagically calculating everyone’s ownership stakes at every round
  • Understanding if your notes convert uncapped, at cap, or discount
  • If a down round is triggered (startups are hard & this happens sometimes), what the broad-based weighted-average anti-dilution protection looks like for all previous equity & noteholders

A note on sharing & privacy

Everyone, including me, is sensitive about their cap tables, so by default the data you create is kept on your local machine only and not sent to any server.

That said, sometimes you want to compare notes with colleagues, advisors, board members, etc. If so, you can enable the sharing toggle, at which point your data has to be sent to a server (so it can then be shared).

Activating sharing

That said, when you’re done sharing, just flip the toggle off. Not only will all the data be deleted from the server, but it will also clear out the shared versions on everyone else’s machines.

Deactivating sharing & deleting the data from the server


  1. I’m not an accountant or attorney, nor do I play one on TV or on Netflix. So please treat this data as directionally accurate and consult with your trusted service providers before making any final decisions on whether to take or pass on that investment offer.
  2. This is software & software has bugs. Especially software written by someone who hasn’t been a full-time engineer for over a decade. If you find bugs, DM me on Twitter and I’ll do my best to squash them.


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