That all depends on How much outside money thepany takes in each round. What the valuation of thepany is in each round. I made a little Excel widget that you can use to figure this out for yourself. You can download it here s In the example I have pre-loaded into the calculator the rounds were as follows $2M raised at an $8M pre-money. $5M raised at a $2M pre-money. $15M raised at a $45M pre-money. In this case the founders own 8% 64% and 48% respectively after each round of funding. Frankly this is a pretty rosy example. Here's a more pessimistic oue from the perspective of the entrepreneurs (perhaps thepany was slower-growing and more cash-intensive) $3M raised at a $5M pre-money. $8M raised at a $13M pre-money. $2M raised at a $25M pre-money. This would lead to the founders owning 63% 39% and 21% after each round. Which leads me to the following point If you want to retain more ownership of yourpany find a way to survive with less outside investment and find ways to increase the perceived value of yourpany (either through faster growth or morepetition between investors). Enjoy the widget and please let me know if it's useful. ( update 7 for more recent analysis on venture and startup operations swing by )