The two numbers that determine how much your company you actually keep

Published: 2026-04-13T10:12:00.000Z

The difference between pre-money and post-money valuation is four words and one equation, but getting it wrong on a term sheet can cost a founder several percentage points of their company before they have signed a single customer. Understanding which number you are negotiating and what it implies for your ownership is not optional financial literacy. It is the most basic thing you need to know before you sit across from an investor.

Every founder who has been through a fundraise has heard the words pre-money and post-money, and a surprising number of them have nodded along without being entirely sure which one they were agreeing to. This is not a matter of intelligence. It is a matter of exposure. The finance industry treats these terms as self-explanatory, investors use them interchangeably in conversation without always clarifying which they mean, and by the time a first-time founder realises the distinction matters, the term sheet is already in front of them and the pressure to move quickly makes careful reading feel like an obstacle rather than a necessity. The concept itself is genuinely simple. Pre-money valuation is what the investor and founder agree the company is worth before the investment comes in. Post-money valuation is what the company is worth after the investment has been added. The relationship between the two is a single equation: pre-money plus the investment amount equals post-money. If an investor agrees to value your company at ten million dollars before their check and then writes a check for five million dollars, the post-money valuation is fifteen million dollars. That arithmetic is not complicated. What gets complicated is what it implies for ownership, and that is where founders who have not done the math in advance discover things they would have preferred to know before signing. The ownership calculation flows directly from the post-money number. When an investor puts five million dollars into a company valued at ten million pre-money, they are buying five million dollars worth of a fifteen million dollar company. Five divided by fifteen is thirty-three percent. That is the investor's ownership stake after the round closes. The founder, who previously owned one hundred percent of the company, now owns approximately sixty-seven percent, assuming no other investors and no employee option pool added before the investment. The pre-money number is what sets the price of the shares being issued. The post-money number is what determines how much of the company each party owns when the dust settles. This is where the pre versus post distinction becomes more than a vocabulary question. When an investor says they are valuing your company at ten million dollars, you need to know immediately whether they mean ten million pre or ten million post, because the answer changes your ownership in a meaningful way. A ten million dollar pre-money valuation on a five million dollar investment produces the thirty-three percent dilution scenario described above. A ten million dollar post-money valuation on the same five million dollar investment implies a pre-money of only five million, which means the investor is buying fifty percent of the company for their five million. Same words, same investment amount, dramatically different outcome for the founder. This is not a hypothetical edge case. It is a real confusion that happens in real fundraising conversations, particularly at the earliest stages when founders are less experienced and investors sometimes use shorthand that assumes knowledge the founder may not have. The option pool is the complication that even founders who understand the basic math often miss on their first raise. Most early-stage term sheets include a requirement to set aside a pool of equity for future employee options, typically somewhere between ten and twenty percent of the post-money capitalisation. The critical question is whether this pool is included in the pre-money valuation or created after the investment. When the option pool is carved out of the pre-money, which is the more common structure in early-stage deals, it effectively reduces the founder's ownership before the investment even happens. A ten million dollar pre-money valuation that requires a fifteen percent option pool carved out pre-investment means the founder's stake is being diluted by the pool creation before they see a single dollar from the investor. The investor's ownership percentage remains based on the clean post-money number, but the founder's effective ownership is lower than the headline pre-money valuation implies. Running the full dilution calculation including the option pool is something every founder should do before agreeing to any term sheet, and it is something that a surprisingly large number of first-time founders do not do until after the fact. To make the progression concrete, consider a founder who takes their company through two rounds. At the seed stage, the company is valued at eight million dollars pre-money and the founder raises one and a half million dollars. The post-money valuation is nine and a half million. The investor owns roughly sixteen percent, and the founder owns approximately eighty-four percent before accounting for any option pool. A year and a half later, the company has grown well and raises a Series A at a pre-money valuation of twenty-five million dollars, with five million dollars coming