Three partners trying to get to equal ownership

My two partners and I formed a corp about a year ago. Setting it up like we each owned 1/3 of the company. While in truth two of us had invested all the capital and the third was doing some of the work. Our true intention was for the third guy to catch up with us and actually be equally invested money wise in the company..... Now that we are working and bringing in $, how do we value what % that the company makes is his. (He's reinvesting what he makes back in, But my partner and I are doing the same, so our stake continues to rise).... Any help would be appreciated

If you have an agreement that says "each of us owns 1/3" then the answer is simple.. 1/3. And there may not be a way to change that and keep the partnership.

If you can approach him in a way that does not turn out badly, you may be able to convince him to put some of his third back in the pot to earn out later.. but you should expect to do the same.

By the way, next time I would suggest that you put some firm milestones in place.. related to things like effort put in or dollars contributed and combine it with a vesting schedule.