Grunt Funds determine exactly how much equity each person in the start-up deserves. The Grunt Fund Calculator spreadsheet will help you keep track of the various contributions each person makes and it will calculate the percentages in real time as it is updated.

The primary calculation is simple:

Contribution of Individual Grunt ÷ Total Contributions from All Grunts = Individual Grunt's Percent of the Pie

This formula, if you think about it, is completely fair. All the theoretical values are determined in a way that applies the right weighting. This keeps everything fair relative to everything else. A brand new truck is relatively more valuable than a 15 year old truck. And, a former SVP of Apple's time is relatively more valuable than a recent high school graduate. It all balances out. So, the formula keeps everything fair and square.