About the Cap Table Calculator
This cap table calculator walks a startup from founding through a post-money SAFE and a priced equity round (seed or Series A). Enter the founders’ shares, any other common stock, the existing option pool, the SAFE amount and valuation cap, and the terms of the priced round — pre-money valuation, amount raised and the option pool the new investors require — and it returns everyone’s ownership at each stage, the round price per share and how many new shares are created.
It is built for founders preparing for a raise, early employees who want to know what their slice is likely to become, and angels checking how a SAFE converts. The table shows each holder at founding, after the SAFE (as-converted at its cap) and after the priced round, and the chart makes the dilution visible stage by stage.
The model follows the standard post-money SAFE mechanics: the SAFE converts at the lower of the cap price and the round price less any discount, and the new pool top-up is created in the pre-money so it dilutes existing holders and SAFE holders but not the new investors. It assumes one SAFE (or several on identical terms entered as one total), one priced round and no anti-dilution or pro-rata adjustments.
With the default inputs, the founders’ combined ownership after the round is 62.31%. Change any value above to recalculate instantly.
How to use the cap table calculator
- 1Enter each founder’s shares, any other common stock and the existing option pool.
- 2Enter the total SAFE investment, its post-money valuation cap and any discount (or 0 if none).
- 3Enter the priced round’s pre-money valuation and the amount being raised.
- 4Set the option pool percentage the investors want after the round.
- 5Read ownership after the round and use the table to compare each stage.
Formula and method
A post-money SAFE buys a fixed percentage of the company equal to the investment divided by the post-money cap, measured against the capitalization just before the priced round (existing shares, options, pool and the SAFE itself, but not a new pool top-up). That makes the cap price (cap − SAFE amount) ÷ existing fully diluted shares. If the priced round is lower than that, or a discount gives a better price, the SAFE converts at the cheaper price instead.
In the priced round, the pre-money valuation is divided across the existing shares, the converted SAFE shares and the pool top-up, so P = pre-money ÷ (S₀ + X + U). The top-up is sized so the unissued pool equals the target percentage of the post-round fully diluted shares. When a discount gives the SAFE a better price than the cap, the SAFE share count depends on the round price, so the calculator solves the price, SAFE shares and pool top-up together in closed form.
- S₀
- Fully diluted shares before the SAFE converts (founders, other common, existing pool)
- X
- Shares issued when the SAFE converts
- U
- New option pool shares created in the pre-money
- E
- Existing option pool shares
- P
- Priced round price per share
Worked examples
$1M SAFE at a $10M cap, then $4M at $16M pre
The SAFE cap price is ($10M − $1M) ÷ 10M shares = $0.90, so the SAFE gets 1,111,111 shares (10% pre-round). The pool is topped up by 444,444 shares, making 11,555,556 pre-money shares and a round price of $16M ÷ 11.56M ≈ $1.3846. Investors take 20%, the pool 10%, SAFE holders 7.69% and the founders keep 62.31%.
Cap-only SAFE above the round price (cap does not bind)
The cap price would be $1.95, but the round is priced lower, so the SAFE converts at the round price. Then P × 10M + $500k = $9M, so P = $0.85 and the SAFE gets 588,235 shares. Investors own exactly 25% of the $12M post-money company and the founders keep 63.75%.
SAFE with a 20% discount and no cap pressure
With a high cap, the 20% discount sets the SAFE price at 80% of the round price, so P × 10M + $1M ÷ 0.8 = $12M and P = $1.075. The SAFE converts at $0.86 into 1,162,791 shares, investors buy 20% of the $15M post-money and the founders keep 64.5%.
Frequently asked questions
What is a cap table?+
A capitalization table lists every security holder in a company — founders, employees with options, the option pool, SAFE and note holders, and preferred investors — with their share counts and percentage ownership, usually on a fully diluted basis.
How does a post-money SAFE convert in a priced round?+
The SAFE converts at the lower of the cap price (post-money cap divided by the company capitalization before the round) and, if it has one, the discounted round price. With a cap-only SAFE that binds, the holder ends up with the investment divided by the cap as a percentage before the new money and pool are added.
Why does the option pool top-up dilute founders but not investors?+
Term sheets usually require the new pool to be counted in the pre-money valuation, so the pool shares are created before the new investors buy in. Investors pay for a percentage of a company that already includes the bigger pool, so existing holders bear all of that dilution.
What does fully diluted mean on a cap table?+
Fully diluted counts every issued share plus all shares that could be issued from options, warrants, the unallocated pool and converting instruments. Ownership percentages and price per share in venture rounds are almost always calculated on this basis.
Can I model several SAFEs with different caps?+
This calculator treats SAFEs as one instrument on identical terms. For SAFEs with different caps, run each with its own cap to see its share, or use a weighted approach; precise multi-SAFE conversion needs every instrument solved together.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.