Key takeaways
- Ownership is investment divided by post-money, not pre-money.
- An option pool carved from the pre-money dilutes founders, not the new investor.
- Convertible instruments create real dilution that is invisible until conversion.
- A valuation cap can give early investors far more than the headline discount implies.
- Liquidation preferences can leave common holders with nothing at a modest exit.
- Model each financing round on the fully diluted share count, including the option pool, before agreeing to terms.
Pre-money and post-money define the denominator
Post-money valuation equals pre-money valuation plus new cash in a simple priced round. Investor ownership is new investment divided by post-money value before considering other simultaneous changes.
Dilution affects every existing holder
If new shares expand the capitalization, each existing percentage falls even though the underlying number of shares may stay the same. Value can still rise if the financing increases company value.
Option pools change the negotiation
A pool increase required before the round generally dilutes existing holders , not the new investor. Model the pool timing and denominator exactly as the term sheet defines them.
Convertibles require a cap-table model
SAFEs and notes may convert using valuation caps, discounts, interest and different definitions of company capitalization. A simple priced-round calculator cannot replace security-by-security modeling.
Pre-money, post-money and the order of operations
Post-money valuation is pre-money plus the amount invested. The investor's ownership is their investment divided by the post-money figure, not the pre-money one. This ordering is the most common source of confusion in early negotiations, because quoting a valuation without specifying which one is meant leaves the actual ownership split undetermined until it is clarified.
The option pool is usually created from the pre-money
Investors typically require an option pool sized to cover hiring until the next round, and typically require it to be established before the investment. That means the pool dilutes existing holders , not the new investor, which effectively lowers the pre-money valuation. A headline valuation with a large pool carved out of the pre-money can deliver less to founders than a lower headline with a smaller pool, which is why the pool is a negotiated term instead of a detail.
Convertible instruments defer the price but not the dilution
Notes and simple agreements convert into equity at a later priced round, often at a discount or subject to a valuation cap. The dilution is real but invisible until conversion, and founders who track only priced rounds are frequently surprised. Any ownership model should convert all outstanding instruments at their expected terms before reporting a percentage.
A valuation cap can dominate the outcome
When a round prices above a cap, the capped instrument converts as though the valuation were the cap, which can give early investors a substantially larger share than the headline discount suggests. The gap between the cap and the eventual price determines how much. Modeling conversion at several possible round prices shows how sensitive the split is, and the sensitivity is often larger than founders expect.
Liquidation preferences determine who gets paid, and in what order
A preference entitles investors to receive their investment back before common holders participate. Whether it is participating or non-participating, and any multiple attached, changes the distribution substantially at moderate exit values. Stacked preferences across several rounds can consume the entire proceeds of a modest exit, leaving common holders with nothing despite a nominally successful outcome. Ownership percentage alone says nothing about this.
Fully diluted ownership is the only meaningful denominator
Fully diluted counts issued shares, the entire option pool including unissued options, warrants, and all convertible instruments as though converted. Any percentage quoted on a different basis is not comparable. Because each round adds instruments, a founder's fully diluted percentage falls faster than a naive share count suggests.
Anti-dilution provisions activate in a down round
If a subsequent round prices below a previous one, anti-dilution provisions adjust earlier investors' conversion terms in their favour, increasing their share at the expense of common holders. Full-ratchet provisions are far more severe than weighted-average ones. These terms are invisible while valuations rise and decisive when they do not, which is exactly when the company can least absorb the effect.
Percentage is not the objective. Value is
Founders sometimes optimize for retaining ownership at the cost of capital the business needs. A smaller share of a substantially larger outcome is worth more than a larger share of a smaller one. The correct question is whether the capital raised produces more value than the ownership it costs, which is a judgement about the business , not an arithmetic result.
Worked with real numbers
What this looks like in the pre-money & post-money valuation calculator
The guidance above is easier to judge against figures. Using the pre-money & post-money valuation calculator worked example, moving pre-money valuation from $6,400,000 to $9,600,000 changes the investor post-money ownership from 17.2% to 23.8%.
| Pre-money valuation | Investor post-money ownership | Holder ownership after financing |
|---|---|---|
| $6,400,000 | 23.8% | 76.2% |
| $7,200,000 | 21.7% | 78.3% |
| $8,000,000 | 20.0% | 80.0% |
| $8,800,000 | 18.5% | 81.5% |
| $9,600,000 | 17.2% | 82.8% |
Open the Pre-Money & Post-Money Valuation Calculator to use your own numbers →
The inputs behind those figures
| Input | Value | Definition |
|---|---|---|
| Pre-money valuation | $8,000,000 | Enter the pre-money valuation for this scenario. |
| New investment | $2,000,000 | Enter the new investment for this scenario. |
| Current holder ownership | 100.0% | Enter the current holder ownership for this scenario. |
What goes wrong
Common mistakes
Each of these produces an answer that looks reasonable, which is why they survive review. To catch them in startup valuation and dilution, rerun the pre-money & post-money valuation calculator with a different assumption and check whether the result moves in the direction the guidance predicts, since an error that survives that test is usually in one of the inputs and not in the arithmetic.
| The mistake | Why it misleads | Do this instead |
|---|---|---|
| Computing ownership against the pre-money valuation | The investor's share is their investment over post-money, so pre-money overstates what founders retain. | Always divide by post-money, and state which valuation any quoted figure uses. |
| Accepting a headline valuation without examining the option pool | A pool created from the pre-money reduces the effective valuation to existing holders. | Model the effective pre-money after the pool and compare offers on that basis. |
| Tracking ownership without converting outstanding notes and safes | Their dilution is real and appears all at once at the next priced round. | Model fully diluted ownership with every instrument converted at expected terms. |
| Judging an exit outcome by ownership percentage | Liquidation preferences are paid first and can absorb the entire proceeds of a modest exit. | Model the waterfall at several exit values, not just the percentage. |
People also ask
Frequently asked questions
Is dilution always bad?
No. A smaller percentage of a substantially more valuable company can be worth more.
Who bears a pre-money option-pool increase?
Typically existing holders. But the documents control.
How much should I raise?
Enough to reach a milestone that justifies a higher valuation, plus a margin for the raise taking longer than planned. Raising too little forces another round from a weak position. Raising far more than needed costs ownership for capital that sits idle. The milestone, not the ownership percentage, should drive the amount.
What does a valuation cap actually do?
It sets a maximum valuation at which a convertible instrument converts. If the priced round is above the cap, the instrument converts as though the valuation were the cap, giving the investor more shares for the same money. The further the round prices above the cap, the larger that effect becomes.
Who does the option pool dilute?
Whoever exists before it is created. Because investors usually require it to be established pre-money, it dilutes founders and earlier holders instead of the incoming investor. So the pool size is a substantive negotiation and not an administrative matter.
What is the difference between participating and non-participating preferred?
Non-participating preferred takes either its preference or its converted common share, whichever is greater. Participating preferred takes its preference and then also shares in the remainder. At moderate exit values the difference to common holders is substantial.
Is dilution always bad?
No. Dilution is the cost of capital, and capital that materially increases the value of the business leaves founders better off in absolute terms despite a smaller percentage. The question is whether the raise buys more value than it costs, not whether ownership falls.
Which input moves the investor post-money ownership most in the pre-money & post-money valuation calculator?
Ranked by how far each moves the investor post-money ownership across the range tested: new investment (3.2%, 16%) and pre-money valuation (3.2%, 16%). Current holder ownership does not change it.
If I double new investment in the pre-money & post-money valuation calculator, does the investor post-money ownership double?
Doubling it from $2,000,000 to $4,000,000 takes the investor post-money ownership from 20.0% to 33.3%, which is 1.67 times the worked-example figure. So it grows, but by less than double. Halving it to $1,000,000 gives 11.1%.