Pre-Money vs Post-Money: Ownership and Option-Pool Math

Pre-money valuation is the negotiated value of a company immediately before new capital enters a priced financing round. Post-money valuation is the pre-money valuation plus the new investment. If a startup raises $2 million at an $8 million pre-money valuation, its post-money valuation is $10 million and the new investor receives 20%: $2 million divided by $10 million.

Founder ownership cannot be calculated from those two dollar amounts alone. You also need the pre-financing cap table and the term sheet’s treatment of options, warrants, convertible securities, and any required option-pool increase. In the consistent example below, the investment by itself reduces the founders from 80% to 64%; requiring a larger employee pool before the financing reduces them further to 60%, even though the headline $8 million pre-money valuation does not change.

Translate the financing offer into three equations

Start by confirming whether the valuation written in the offer is pre-money or post-money. The distinction changes the denominator used to calculate the investor’s stake. The CRV financing guide gives the core relationships: post-money valuation equals pre-money valuation plus investment, investor ownership equals investment divided by post-money valuation, and share price equals pre-money valuation divided by the pre-money fully diluted share count.

Written as equations, the first two relationships are:

Post-money valuation = pre-money valuation + new investment
New investor ownership = new investment ÷ post-money valuation

For an $8 million pre-money valuation and a $2 million investment, the post-money valuation is $10 million. The investor’s implied ownership is $2 million ÷ $10 million = 20%. Existing holders collectively retain 80% after the round, before accounting for any separate issuance or pool adjustment.

Do not divide the investment by the pre-money valuation. Doing so would produce 25%, but that number expresses the investment as a percentage of the company’s value before the cash arrives; it is not the investor’s percentage of the post-financing company.

Build the baseline cap table before calculating dilution

Consider a hypothetical startup with 8 million founder shares and 2 million unissued shares already reserved in its employee option pool. For this simplified example, there are no other stockholders, outstanding employee options, warrants, SAFEs, convertible notes, or secondary sales.

Founder shares: 8,000,000
Existing unallocated option pool: 2,000,000
Pre-money fully diluted shares: 10,000,000
Founder ownership before financing: 8,000,000 ÷ 10,000,000 = 80%
Unallocated pool before financing: 2,000,000 ÷ 10,000,000 = 20%

Using the fully diluted denominator matters because the reserved pool represents shares that may be issued without another financing. If the term sheet defines fully diluted capitalization differently, substitute its definition rather than assuming the example’s denominator applies.

The phrase “founders own 80%” therefore does not mean that another investor already owns the remaining 20%. In this example, the difference is an unallocated reserve. Separating issued founder shares from reserved but unissued shares makes the later dilution visible.

Convert valuation into price per share and new shares

Share-price calculation reconciling an $8 million pre-money valuation and $2 million investment with 64% founder ownership and 20% investor ownership.

With no pool increase, divide the $8 million pre-money valuation by 10 million pre-money fully diluted shares. The financing price is $0.80 per share. A $2 million investment therefore purchases 2.5 million new preferred shares: $2 million ÷ $0.80.

Founder shares after closing: 8,000,000
Unallocated option-pool shares: 2,000,000
New investor shares: 2,500,000
Post-financing fully diluted shares: 12,500,000

The ownership results reconcile with the valuation shortcut. The investor holds 2.5 million ÷ 12.5 million = 20%. Founders hold 8 million ÷ 12.5 million = 64%, while the unallocated pool represents 2 million ÷ 12.5 million = 16%.

You can also calculate founder ownership without first finding the new share count. Existing holders retain 1 minus the investor percentage, or 80% of the post-financing company. The founders held 80% of the pre-financing fully diluted capitalization, so their resulting stake is 80% × 80% = 64%. The share calculation remains useful because it exposes whether the proposed capitalization includes every security and reserve.

Work backward from a requested investor percentage

A term sheet may state the investment and target ownership rather than clearly displaying both valuations. In that case, calculate the post-money valuation by dividing the investment by the investor’s post-closing percentage. Then subtract the investment to recover the pre-money valuation.

Post-money valuation = investment ÷ investor percentage
Pre-money valuation = post-money valuation − investment
Pre-money valuation = investment × (1 − investor percentage) ÷ investor percentage

For $2 million invested for 20%, the post-money valuation is $2 million ÷ 20% = $10 million. The pre-money valuation is $10 million − $2 million = $8 million. Wall Street Prep’s valuation explanation demonstrates the same reverse calculation from investment size and implied ownership.

You can also solve for the investment required to sell a chosen percentage at a known pre-money valuation: investment = pre-money valuation × investor percentage ÷ (1 − investor percentage). At an $8 million pre-money valuation, selling 20% implies an investment of $8 million × 20% ÷ 80% = $2 million.

Model a pre-money option-pool increase

Pre-money option-pool increase lowering the share price and founder ownership while preserving the investor’s 20% stake.

The simple 64% founder result changes if the investor requires enough unallocated options to equal 20% of the company immediately after closing. Without a top-up, the existing 2 million-share pool would be only 16% after the financing, so additional shares must enter the pre-money denominator.

This placement is economically important. Carta’s option-pool guidance explains that a pool increase is typically included in pre-money shares, lowering the financing price per share and preventing the increase from diluting the new investor; an increase made after financing would instead dilute all stockholders, including that investor.

Let x be the new pool shares required. Because the $2 million investment equals 25% of the $8 million pre-money valuation, investor shares will equal 25% of the expanded pre-money share count. The target equation is:

(2,000,000 + x) ÷ ((10,000,000 + x) × 1.25) = 20%

Solving it produces approximately 666,667 additional pool shares. Pre-money fully diluted capitalization becomes approximately 10,666,667 shares, and the $8 million valuation produces a lower price of approximately $0.75 per share. The investor buys approximately 2,666,667 shares for $2 million.

Founder shares: 8,000,000
Total unallocated pool: approximately 2,666,667
Investor shares: approximately 2,666,667
Post-financing fully diluted shares: approximately 13,333,334
Founder ownership: approximately 60%
Unallocated option pool: approximately 20%
Investor ownership: approximately 20%

Minor differences may appear when a legal capitalization schedule rounds the price or share counts. The exact closing model should use the term sheet’s precision and the company’s actual capitalization rather than rounded figures from this illustration.

Compare the two deals with the same headline valuation

Both versions use an $8 million pre-money valuation and a $2 million investment. Both give the investor 20% immediately after closing. Yet founders retain 64% when no pool top-up is required and approximately 60% when the unallocated pool must equal 20% post-closing.

The four-percentage-point difference is the option-pool shuffle made visible. The top-up does not transfer already issued founder shares to employees at closing; it expands the fully diluted denominator with additional reserved shares. Whether those options are eventually granted is a separate question, but the financing price already reflects their inclusion.

It is also useful to distinguish percentage points from percentage decline. Moving from 64% to 60% is a loss of four percentage points, equivalent to a 6.25% reduction relative to the founders’ 64% no-top-up result. Moving from 80% before the transaction to 60% afterward is a 20-point reduction, or a 25% relative decline.

Audit the term sheet before accepting its ownership summary

Ask for a pro forma cap table in shares and percentages, both before and after the financing. A headline valuation is insufficient if you cannot reproduce the price per share and every holder’s resulting percentage.

Confirm whether the quoted valuation is pre-money or post-money and whether the investment is entirely new primary capital.
Identify the fully diluted share definition, including issued common and preferred stock, granted options, the unallocated pool, warrants, and securities that convert in the round.
Separate the current unallocated pool from the target pool. Confirm whether the target is measured before or after financing and whether it refers to ungranted shares or the entire equity plan.
Calculate post-money valuation, investor percentage, price per share, and new investor shares independently.
Rebuild the post-closing denominator and verify that all ownership percentages sum to 100%.
Run a second scenario with no pool increase, then quantify how much founder ownership the requested top-up costs.
Compare the requested reserve with a role-by-role hiring and equity-grant plan through the next expected financing rather than treating a round percentage as self-justifying.

Also isolate any secondary transaction in the model. The basic formula assumes that the investment is new capital entering the company; a purchase of existing shares must be modeled separately to avoid misstating cash proceeds and ownership.

Know where the simplified formulas stop

This model describes a straightforward priced equity round. SAFEs, convertible notes, accrued interest, valuation caps, discounts, warrants, multiple closing dates, pay-to-play terms, and anti-dilution adjustments can change the share count or price calculations. Liquidation preferences can also make economic proceeds differ from headline ownership percentages.

Pre-money valuation is therefore not a complete measure of deal quality, nor is it an appraisal of what every security would receive in an exit. It is a pricing input for the financing. Legal documents and the capitalization model determine how that input interacts with the actual securities.

Use the formulas to challenge inconsistencies and compare scenarios, but have the company’s counsel and qualified finance or tax advisers review the definitive documents. The practical deliverable you want before signing is a cap table where each input is named, each formula can be reproduced, and the option-pool burden is shown as its own line rather than hidden inside “fully diluted shares.”

Turn the offer into a decision-ready model

Put the current cap table, proposed investment, valuation basis, conversion assumptions, and pool target into one pro forma. Keep separate columns for the no-top-up case and the investor’s requested case. That comparison converts valuation language into the two outputs that matter for this decision: how much of the company each party owns at closing and which existing holders absorb any extra dilution.

Pre-Money vs Post-Money Valuation: Calculate Ownership and Option-Pool Dilution