Pre-Money and Post-Money Valuation Calculator

Every priced equity round rests on one sentence: an investor agrees to pay a certain amount of money for a certain percentage of the company. Pre-money valuation and post-money valuation are two ways of describing the same agreement. The pre-money valuation is what the company is deemed to be worth immediately before the new cash arrives. The post-money valuation is what it is deemed to be worth immediately afterward, which means the pre-money figure plus the new money. If a company is valued at $6 million pre-money and receives $2 million, the post-money valuation is $8 million, and the investor owns $2 million divided by $8 million, or 25 percent.

The reason founders confuse the two numbers is that people say 'we raised at an $8 million valuation' without saying which one they mean. A pre-money valuation of $8 million with a $2 million check produces a post-money valuation of $10 million and investor ownership of 20 percent. A post-money valuation of $8 million with the same check gives the investor 25 percent. That five-point difference in ownership is real equity leaving the founders' hands, so the label is not cosmetic. Always ask which one is being quoted, and always convert the answer into a percentage of the fully diluted company before reacting.

Four relationships do all the work. First, post-money valuation equals pre-money valuation plus the investment amount. Second, the new investor's ownership equals the investment divided by the post-money valuation. Third, the existing shareholders collectively own one minus that percentage, because everyone's stake shrinks by the same proportion. Fourth, the price per share equals the pre-money valuation divided by the fully diluted pre-money share count, and the number of new shares equals the investment divided by that price.

These formulas are consistent with one another, which is a useful check. If the pre-money valuation is $12 million and there are 8 million fully diluted shares, the price is $1.50. A $3 million investment buys 2 million new shares. After closing there are 10 million shares, and the investor holds 20 percent, which equals $3 million divided by a post-money valuation of $15 million. If your own spreadsheet disagrees with that triangle of price, shares and percentage, one of the inputs is probably using a different share count, usually because an option pool, a warrant or a converting note was left out.

The phrase fully diluted deserves precision. It normally counts issued common and preferred shares, outstanding options, reserved but unissued options in the pool, warrants, and any convertible securities that will convert in the round. Using only issued shares understates the denominator, overstates the price per share, and quietly shortchanges the new investor, who will usually insist on a corrected calculation in the term sheet.

Imagine two founders who hold 5 million shares each, 10 million in total, with no options issued and no notes outstanding. A seed investor offers $1 million at a $4 million pre-money valuation. The post-money valuation is $5 million, so the investor receives 20 percent. The price per share is $4 million divided by 10 million, or $0.40. The investor buys 2.5 million new shares for $1 million, bringing the total to 12.5 million. Each founder now holds 5 million out of 12.5 million, which is 40 percent, down from 50 percent.

Notice what dilution means here. Founders did not lose value; they hold a smaller percentage of a larger company. Before the round each founder's stake was worth $2 million at the agreed price. Afterward each holds 40 percent of a $5 million company, which is still $2 million on paper. The founders' paper wealth is unchanged at closing, but the company now has $1 million of additional resources. Dilution is only costly if the new capital fails to increase the value of the company by more than the stake sold. That framing is the right lens for every calculation on this page.

Run the same deal at a $3 million pre-money valuation and the investor owns 25 percent; at $5 million pre-money, the investor owns about 16.7 percent. A one-million-dollar move in pre-money valuation changes founder ownership by roughly three to five points here, which is why small-looking changes in headline valuation are worth negotiating but not worth sacrificing important terms for.

Now consider a company with 10,000,000 fully diluted shares after an earlier round. A Series A lead proposes $6 million at an $18 million pre-money valuation. The post-money valuation is $24 million, and the new investors receive 25 percent. The price per share is $18 million divided by 10 million, or $1.80. New shares equal $6 million divided by $1.80, which is 3,333,333, giving a post-closing share count of 13,333,333. The new investors hold 3,333,333 divided by 13,333,333, exactly 25 percent.

Every existing holder is scaled by the same factor of 0.75. A seed investor who held 8 percent before the round holds 6 percent afterward. A founder with 30 percent holds 22.5 percent. An employee with 0.2 percent holds 0.15 percent. This uniform scaling is the reason a cap table can be updated by multiplying each existing percentage by one minus the new investor's percentage, as long as nothing else is issued in the same round.

Check the arithmetic in dollars as well. The founder's 22.5 percent of $24 million equals $5.4 million, while 30 percent of the $18 million pre-money was also $5.4 million. Again the paper value is unchanged at closing. A different founder holding 3,000,000 shares sees 3,000,000 shares at $1.80 equal $5.4 million, which confirms that the percentage and share-price views agree. When they do not, a pool increase or rounding convention is usually involved.

Investors commonly require that a specified percentage of the post-money company be reserved as an unallocated option pool for future hires, and they often specify that the pool is created before the round so it dilutes only existing holders. The effect is that the effective pre-money valuation, meaning the value attributed to the founders' existing shares, is lower than the headline number. This practice is sometimes called the option pool shuffle.

Take a headline pre-money valuation of $12 million with a $3 million investment, producing a $15 million post-money valuation and a 20 percent stake for the investor. Suppose the term sheet requires a 10 percent post-money unallocated pool. The pool is worth 10 percent of $15 million, or $1.5 million. The effective pre-money valuation for existing holders is therefore $12 million minus $1.5 million, or $10.5 million. Existing holders collectively own 100 minus 20 minus 10, which is 70 percent of the post-money company.

In shares: if the founders hold 8,000,000 shares and nothing else exists, 8,000,000 must equal 70 percent of the post-closing total, so the total is 11,428,571. The investor receives 20 percent, or 2,285,714 shares, and the pool is 10 percent, or 1,142,857 shares. The price per share is $3 million divided by 2,285,714, which is $1.3125. Multiply that price by the founders' 8,000,000 shares and you get $10.5 million, matching the effective pre-money valuation. Had the pool been absent, the price would have been $1.50, so the pool reduced the price by 12.5 percent.

None of this makes a pool unreasonable. A pool that is sized to a real hiring plan is useful, and a smaller pool backed by a written plan can often be negotiated. The point is that the pool must be modeled explicitly, because comparing two term sheets by headline valuation alone can reverse the ranking once the effective pre-money valuations are computed.

Many early companies raise through convertible notes or SAFEs before a priced round, and these instruments change the arithmetic. A post-money SAFE, as popularized by Y Combinator, sets a valuation cap that includes the SAFE money itself in the capitalization used for conversion. A $500,000 SAFE at an $8 million post-money cap therefore represents 6.25 percent of the company measured immediately before the priced round, because $500,000 divided by $8 million is 0.0625. A founder who knows that figure can see right away how much of the company has already been sold, regardless of how many other SAFEs are signed.

Older pre-money SAFEs and many convertible notes work differently: the cap is applied to a capitalization that excludes the instruments themselves, so the ownership they convert into depends on how many other notes exist and gets larger as more are signed. Because of this, the percentage ownership given away is harder to see in advance, which is one reason post-money SAFEs became popular. Specific definitions of company capitalization vary by document and, notably, in how pool increases are treated, so read the instrument itself rather than relying on a summary.

A discount works through price rather than valuation. If a note holder has a 20 percent discount and the new round price is $2.00, the note converts at $1.60. A $300,000 note converts into 187,500 shares before any accrued interest, compared with 150,000 shares an investor putting in $300,000 at $2.00 would receive. When both a cap and a discount exist, the holder typically receives the lower of the two conversion prices. A calculator that ignores conversion will understate the dilution at the next priced round, so enter converting amounts into the pre-round share count when you model it.

Dilution compounds multiplicatively, not additively. Suppose a founder starts with 100 percent of a company, sells 20 percent at seed, 20 percent at Series A, and 15 percent at Series B. The founder does not hold 45 percent; the retained share is 0.80 times 0.80 times 0.85, which equals 0.544, or 54.4 percent of the original stake. Add a 10 percent pool refresh at Series A, and that round's retained factor becomes 0.70 instead of 0.80, producing 0.80 times 0.70 times 0.85, or 47.6 percent.

A helpful habit is to record retention factors by round. Seed retention of 0.85 means existing holders kept 85 percent of their stakes. When teams discuss dilution targets, they typically think in terms of per-round ranges, then verify the cumulative outcome. A company that sells 20 percent per round across four rounds leaves existing holders with 0.8 to the fourth power, which is about 41 percent, and that does not yet account for pools. Founders who want to retain meaningful control through later stages should build the multi-round view before accepting an early valuation, not after.

Equally important, a higher valuation does not guarantee a better result. A round at a high valuation that the company cannot grow into can lead to a flat or down round later, which triggers anti-dilution protection and more severe dilution. The right comparison is not 'which valuation is highest today' but 'which capital, terms and valuation give the company the best chance of reaching its next milestone with a financing it can actually win.'

A calculator tells you about ownership, but investor rights determine what ownership is worth. Liquidation preferences decide who is paid first when the company is sold. A 1x non-participating preference lets the investor choose between getting its money back or converting to common, whichever is larger. A participating preference lets the investor take its money back and also share in the remainder, which can materially reduce what founders receive in a modest exit. A 2x multiple doubles the preference.

Board composition, protective provisions, pro rata rights, information rights and drag-along terms all shape the practical control of the company. Pro rata rights allow an investor to buy a share of future rounds to maintain ownership, which affects how much room exists for new investors. Anti-dilution protections adjust conversion prices if the company later sells shares at a lower price; broad-based weighted average protection is the most common, while full ratchet is far more aggressive.

Use the calculator to quantify the percentages, then compare term sheets using a short list of non-price terms. A slightly lower valuation with a cleaner preference and a smaller pool can leave founders better off than a higher valuation with a participating preference and a large pre-money pool. When the two offers differ in several terms at once, model a few exit values, such as $20 million, $60 million and $150 million, to see how proceeds divide.

The most frequent mistake is mixing definitions: using a post-money number as if it were pre-money, or applying an ownership percentage to the wrong base. A second is excluding the option pool, outstanding warrants or converting securities from the share count. A third is treating the investment as the total of the round when multiple investors, including existing ones exercising pro rata, are contributing. A fourth is rounding the share price to two decimals too early; investors often use four or more decimals, and rounding can shift share counts by thousands.

Cross-check every scenario with three tests. First, post-money minus pre-money should equal the new money. Second, new investor shares divided by the post-closing share count should equal investment divided by post-money. Third, price per share times post-closing shares should equal the post-money valuation. If all three agree, the arithmetic is internally consistent, even if the inputs themselves still need verification against the cap table and legal documents.

Also remember that tranche or milestone-based investments complicate the picture. If an investor commits $2 million but funds $1 million now and $1 million later at the same price, the post-money valuation implied at closing is not the same as the headline, and ownership grows only as cash arrives. Model each tranche separately, and note whether the later funding is optional or obligatory.

Enter the pre-money valuation, the investment amount, and, if you have it, the existing share count and any required pool. Read the result as a map of the proposal: post-money valuation, new investor percentage, price per share, new shares and updated founder ownership. Then change one input at a time. Move the pre-money valuation by a million dollars, shrink the pool by two points, or add a second investor, and observe how each change moves the founders' retained percentage.

The calculator is a simplified educational model. It does not interpret the definitions in your term sheet, evaluate preferences, taxes or securities-law compliance, or understand your jurisdiction. The estimates it produces are not an appraisal, a valuation opinion or legal advice, and they should not be used as the sole basis for signing documents. Before closing a financing, reconcile the numbers with your current capitalization table and have a qualified securities lawyer and, where appropriate, a tax adviser review the final documents.