# Calculation of IRR Given Stage Assumptions

I am trying to replicate Union Square Ventures Fund #1 model.

A number of assumptions are given and the outcomes are listed. I have copied these into google sheets.

I am not sure exactly how IRR is calculated.

In order to compute Cash Out, I am assuming Average Initial Investment, Average Follow On Investment, Inital Investments per Year, Winners, Losers, Money Back, Rounds Per Investment, and Deals Per Stage are used:

1) Cash-Out Year N = (Average Investment Amount * Number of Initial Investments for Year N) + (Average Follow On Investment / Rounds Per Investment)

In order to to compute Cash In, I assuming Winners, Money Back, Losers, Average Return Multiple, Average Holding Period and Average Total Investment are used:

2) Cash-In Year N = Average Return Multiple * (Average Initial Investment + Average Follow On Investment) [with lag of N - Average Holding Period]

However, I am unsure mostly on how on each year the number of each type of deal concept, trial, revenue and outcomes winners, money back, losers are inputed/factored in.

Equation 1) and 2) above are my guesswork, and I would appreciate advice on how to amend and implement them.