Small early checks can accumulate into a meaningful stake.
For compatible post-money SAFEs whose caps govern conversion, purchase amount divided by post-money cap estimates each holder’s ownership before new priced-round money. Adding these fractions exposes the aggregate burden on the original capitalization.
This is a cap-governing ownership approximation, not a document engine. A near-cap or below-cap priced round can change conversion economics. Financing-related pool increases and pro-rata purchases also change the final ownership.
The formula, made clear.
- Compatible post-money caps
- Each cap is measured after SAFE money but before the new priced-round money.
- Original capitalization
- The holders and reserve before the entered SAFE stack.
Put the numbers in context.
A 500,000 SAFE at a 5 million cap implies 10%, and another 500,000 at a 10 million cap implies 5%. A later round issuing 20% leaves the stack with 12% and the original capitalization with 68%.
| Input | Example value |
|---|---|
| SAFE A investment | $500,000.00 |
| SAFE A post-money cap | $5,000,000.00 |
| SAFE B investment | $500,000.00 |
| SAFE B post-money cap | $10,000,000.00 |
| SAFE C investment | $0.00 |
| SAFE C post-money cap | $10,000,000.00 |
| New priced-round ownership | 20% |
| SAFE stack ownership after new money | 12% |
What this calculation assumes
At most three post-money cap-only positions with caps governing conversion; zero amounts omit positions. No discounts, MFN, pre-money SAFEs, pool increase, interest or pro-rata purchases. Not a precise below-cap round conversion.
Methodology references
What to consider next.
Use the actual financing documents and priced-round capitalization to validate conversion. Add the option-pool effect separately.
How we approach financial models →