Calculator
Cap table and dilution simulator
Add your SAFEs and notes, set the round, and see the price per share, each investor's conversion and the cap table after the round.
This simulator takes a company's current shares, any SAFEs and convertible notes, and a priced round, and works out the round's price per share, how many shares each SAFE and note converts into, the option-pool top-up and the cap table after the round. It runs entirely in your browser; nothing you enter is sent anywhere. The engine follows the conventions of Y Combinator's post-money SAFE guide and reproduces its worked examples (see validation).
| Instrument | Converting | Converts at | Shares | Price paid |
|---|---|---|---|---|
| Pre-seed SAFEs | $500,000 | valuation cap | 1,052,631 | $0.4750 |
| Seed SAFEs | $2,500,000 | valuation cap | 1,578,947 | $1.5833 |
| Holder | Shares | Fully diluted |
|---|---|---|
| Founder 1 | 4,500,000 | 26.18% |
| Founder 2 | 4,500,000 | 26.18% |
| Options granted | 400,000 | 2.33% |
| Available option pool | 1,718,797 | 10.00% |
| Pre-seed SAFEs | 1,052,631 | 6.12% |
| Seed SAFEs | 1,578,947 | 9.19% |
| New investors | 3,437,607 | 20.00% |
| Total | 17,187,982 | 100.00% |
| Price per share | $2.9090 | |
This is the worked example below. Turn on JavaScript to change the inputs.
The example, step by step
The default inputs describe the example company used across this site: two founders with 9,000,000 shares, 400,000 options granted and 600,000 in the pool (10,000,000 fully diluted). It raised $500,000 on post-money SAFEs at a $6 million cap and $2.5 million at a $20 million cap, and now raises a $10 million Series A at $40 million pre-money with a 10% available pool afterwards.
- SAFE ownership before the round. $500,000 ÷ $6 million = 8.33%, and $2.5 million ÷ $20 million = 12.50%; together 20.83% of the post-SAFE company.
- Company Capitalization (the post-money SAFEs' denominator) = 10,000,000 ÷ (1 − 20.83%) = 12,631,579 shares. The SAFEs convert into 1,052,631 and 1,578,947 shares.
- Pool increase of 1,118,797 shares, so that 1,718,797 unissued options are 10% of the post-round total.
- Price per share = $40,000,000 ÷ (10,000,000 + 2,631,578 + 1,118,797) = $2.9090.
- New shares = $10,000,000 ÷ $2.9090 = 3,437,607, exactly 20% of the company after the round.
The founders go from 90% to 71.3% after the SAFEs (as converted) and to 52.4% after the Series A.
The rules the simulator applies
- Post-money SAFE: shares = Company Capitalization × amount ÷ cap, where the capitalization includes all shares, options (granted and promised), the existing pool and all converting securities, but not the round's pool increase.
- Pre-money SAFE and convertible note: cap price = cap ÷ (existing fully diluted shares + pool increase), excluding converting securities. Notes convert principal plus simple interest for the months entered.
- Discount: discount price = round price × (1 − discount). Each instrument converts at whichever of its cap, discount or the round price gives the most shares.
- Price per share = pre-money ÷ (existing shares + conversion shares + pool increase), rounded to $0.0001; shares are rounded down.
- Pro rata side letter (post-money SAFEs): the holder buys its as-converted percentage of the new shares, out of the round.
What it leaves out
- Existing preferred stock from an earlier priced round is treated like common for share counts; a second priced round with its own anti-dilution or pay-to-play terms needs a lawyer's model.
- Notes whose cap is defined post-money, or that count other notes in the capitalization, convert differently; check your note's definitions.
- Warrants, multiple closings at different prices, and taxes are not modeled.
- The ownership chart lumps granted options with the pool, and all founders together.
See also: what each holder receives in a sale and SAFE vs note on the same terms.
Sources
- Post-Money Safe User Guide, Y Combinator. Cited for facts; not reproduced.