The short answer
How much ownership does a post-money SAFE sell?
For a cap-only post-money SAFE converting at its cap, investment divided by the post-money cap is a useful starting estimate of ownership sold before the new money in a later priced round. Additional financing and an option-pool increase can dilute that stake. Read the instrument’s capitalization and conversion definitions.
Start with two small rounds of funding
In this simplified case, a company has founders only, no existing option pool and two cap-only post-money SAFEs that convert at their caps. A $500,000 SAFE at a $5 million cap represents 10%. A second $500,000 SAFE at a $10 million cap represents 5%. Founders retain 85% before new priced-round money and any option-pool increase.
Now assume new investors buy 20% of the company after the priced round and there is no pool increase. Multiply the existing stakes by 80%: founders hold 68%, the first SAFE holders 8%, the second SAFE holders 4% and the new investors 20%. Those percentages add to 100%.
If a newly created option pool instead receives 10% of the final company and new investors still receive 20%, the earlier holders collectively keep 70%. In this explicit allocation example, founders hold 59.5%, SAFE holders hold 7% and 3.5%, the pool holds 10% and new investors hold 20%. This is an ownership illustration, not a share-price calculation for a negotiated financing.
References: Y Combinator: SAFE documents and user guide
Why the actual cap table can differ
A SAFE is a contract for future equity; a standard YC SAFE is not a loan with interest and a maturity date. A convertible note is a different instrument. A discount-only SAFE, a pre-money SAFE, multiple instrument types or a round below the cap needs its own conversion math.
A valuation cap is a conversion term, not an independent appraisal of the business. Pro rata rights can allow an investor to buy more securities in a later financing; they do not prevent dilution for free. Reconcile the final share counts using the actual financing documents and the option-pool convention.
References: Y Combinator: SAFE documents and user guide
Try it yourself
Track the ownership after new funding
Two cap-only post-money SAFEs converting at their caps; founders only before the SAFEs. No existing options, notes or other securities. The new-money and new-pool percentages are explicit final ownership allocations, not a negotiated share-price model.
| Holder | Before new money / pool | Final ownership |
|---|---|---|
| Founders | 85.0% | 68.0% |
| First SAFE | 10.0% | 8.0% |
| Second SAFE | 5.0% | 4.0% |
| New investors | — | 20.0% |
| New option pool | — | 0.0% |
| Total | 100.0% | 100.0% |
Rounded display percentages may differ slightly from 100%; the underlying shares reconcile. Actual conversion requires the signed instrument and financing definitions.
Use a cap table before accepting the money
Record every instrument’s cash invested, cap, discount, conversion definition and side-letter rights. Model the financing you are planning, then a larger raise and a lower valuation. The percentage sold should be understood before a signature, not discovered during the priced round.
- Separate pre-money and post-money instruments.
- State whether ownership includes existing options, reserved shares and a new pool.
- Include every SAFE and note in the same model.
- Reconcile all post-financing ownership percentages to 100%.
One-minute check
Can you explain the difference?
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Common questions
A few useful clarifications
Is a $5 million SAFE cap the same as a $5 million priced-round valuation?
No. The SAFE cap governs conversion under the instrument. A priced financing establishes a share price and negotiated capitalization. Their economic effect depends on the definitions and new money.
Can I just divide investment by the cap for every SAFE?
No. That shortcut is for the stated cap-only post-money case converting at the cap. Different SAFE versions, discounts, a low-priced round and other instruments can change the calculation.
Sources & scope
Reviewed October 9, 2026. Numerical cases are fictional teaching examples, not current market quotes or individual advice. Assumptions appear beside each calculation. Rules, program requirements and source material can change.
- Y Combinator: SAFE documents and user guidePost-money SAFE framework, forms and conversion explanations. The numerical cap table is a simplified teaching illustration.
Keep going
Use what you learned.
Use the SAFE calculator
Explore the course calculator’s conversion assumptions.
Compare SAFEs and convertible notes
Understand how the instruments differ before modeling them.