Cap Table with SAFE and Convertible Note Conversion: option pool top-up, dilution, exit waterfall

The cap table founders and seed investors argue about, with the arithmetic done properly. Post-money SAFEs convert at cap over company capitalisation including all SAFE shares, which is circular; this workbook solves it in closed form instead of guessing. Notes convert at the lower of their cap price and the discounted round price. The option pool is topped up in the pre-money to a target share of post-money capital, also in closed form. Then the round is priced, every holder's dilution is shown, and an exit waterfall splits the proceeds.

• Inputs: existing holders and classes, post-money SAFEs (amount, cap, discount), convertible notes (principal, accrued interest, cap, discount), the priced round (pre-money, new money, target pool share, lead investor), exit value and preference multiple.

• Conversion: the SAFE capitalisation solution (total SAFE shares = N0 x / (1 - x)), cap prices, discount test, shares per instrument; pass 1 on caps, pass 2 with the discount test; pool top-up, pre-money fully diluted shares, round price, new investor shares, post-money shares and two checks.

• Cap table: shares and percentage before and after, dilution in percentage points, value at the post-money for every holder, founders' combined ownership.

• Exit waterfall: the new round takes the greater of its 1x non-participating preference and its as-converted share; the rest is shared pro rata; proceeds, share of exit and multiple on money for every holder.
  
  

Rebuilt independently in Python from the same inputs and matched cell by cell before listing. The Guide states every convention (post-money SAFE, pre-money note cap, pre-money pool top-up, zero-strike options in the waterfall) so you can change the one your documents differ on. Live formulas, no macros, no locked cells. Excel and Google Sheets.

Who it is for: founders modelling a round before the term sheet, angels and seed funds checking a proposed cap table, accelerator and law-firm teams who need the mechanics in a file the client can read.