cap-table
Work out who owns what in a startup through its SAFEs, convertible notes and a priced round — each SAFE's and note's conversion price and whether its cap or discount applied, the price per share, the option-pool top-up and who it dilutes, the fully diluted cap table before and after, and founder ownership at other valuations — computed by a script that checks the post-money and the 100 % total. Use when a founder asks "how much of my company will I own after this round", "model our SAFEs converting", "what does this term sheet do to our cap table", "how much have I given away in SAFEs", or "compare a $12M and a $16M pre-money".
Other ways to install
With the sibling skills it hands off to:
The whole pack it belongs to:
By hand, from a clone of the repo:
In Claude Code, with the startup-legal plugin installed, invoke it as:
Try it
A realistic prompt from the skill's acceptance evals:
Two founders, 4.5M shares each. 250k options granted, 750k unissued in the pool. SAFEs: $500k post-money at $8M cap; $125k post-money at $6M cap with 20% discount; $100k pre-money SAFE at $5M cap, 20% discount. Plus a $50k note at 6% from 2025-06-01, $5M cap, 20% discount. Term sheet: $16M pre, $4M lead + $1M follow-on, 10% pool post-money, closing 2026-12-15. What do we each own after?
What a good result looks like
Example output
Worked example: three SAFEs and a note into a Series A · the skill's own worked example, source
Input
"We're two founders with 4.5M shares each, 250k options granted and 750k left in the pool. We raised $500k on a post-money SAFE at an $8M cap, $125k from an accelerator (post-money, $6M cap, 20 % discount), $100k from an early angel on the old pre-money SAFE ($5M cap, 20 % discount), and a $50k friends-and-family note at 6 % from June 2025 ($5M cap, 20 %). The term sheet: $16M pre, $4M from the lead and $1M follow-on, 10 % option pool post-money, closing mid-December. What do we each end up with?"
Input written (in a private temporary folder)
{
"company": "Example Labs, Inc.",
"currency": "USD",
"holders": [
{"name": "Founder A", "class": "common", "shares": 4500000},
{"name": "Founder B", "class": "common", "shares": 4500000}
],
"options": {"granted": 250000, "pool_unissued": 750000},
"safes": [
{"holder": "Angel syndicate", "amount": 500000, "type": "post", "cap": 8000000},
{"holder": "Accelerator", "amount": 125000, "type": "post", "cap": 6000000, "discount": 0.2},
{"holder": "Early angel", "amount": 100000, "type": "pre", "cap": 5000000, "discount": 0.2}
],
"notes": [
{"holder": "Friends and family note", "principal": 50000, "rate": 0.06, "issued": "2025-06-01", "cap": 5000000, "discount": 0.2}
],
"round": {
"pre_money": 16000000,
"investors": [{"name": "Series A lead", "amount": 4000000}, {"name": "Series A follow-on", "amount": 1000000}],
"pool_target": 0.10,
"close": "2026-12-15"
}
}Reply
After the Series A you each own 28.3 %, down from 45 % today. The new investors take 23.8 %, the SAFEs and note 8.0 % together, and the option pool 11.6 %.
| Holder | Class | Shares | % |
|---|---|---|---|
| Founder A | common | 4,500,000 | 28.30 |
| Founder B | common | 4,500,000 | 28.30 |
| Angel syndicate | preferred (safe) | 704,673 | 4.43 |
| Accelerator | preferred (safe) | 234,891 | 1.48 |
| Early angel | preferred (safe) | 216,801 | 1.36 |
| Friends and family note | preferred (note) | 118,415 | 0.74 |
| Series A lead | preferred (round) | 3,028,714 | 19.05 |
| Series A follow-on | preferred (round) | 757,178 | 4.76 |
| Options granted | options | 250,000 | 1.57 |
| Option pool, unissued | options | 1,590,074 | 10.00 |
| Total | 15,900,746 | 100.00 |
What each SAFE and note converted at. All four convert at their caps; none of the discounts gives a lower price at $1.3207 a share.
| SAFE or note | Invested (with interest) | Converts at | By | Shares |
|---|---|---|---|---|
| Angel syndicate (post-money safe) | $500,000 | 0.7095 | cap | 704,673 |
| Accelerator (post-money safe) | $125,000 | 0.5322 | cap | 234,891 |
| Early angel (pre-money safe) | $100,000 | 0.4613 | cap | 216,801 |
| Friends and family note (pre-money note) | $54,619 | 0.4613 | cap | 118,415 |
What the pool top-up costs you. The term sheet's 10 % pool has to be topped up by 840,074 shares, and they come out of the pre-money. That makes the $16M headline worth $14.9M to the existing holders: about $1.1M of the valuation goes to future hires before you've hired them. If the lead agreed to top up the pool after the round instead, you'd each hold 28.8 %, half a point more.
Assumptions
[assumption]The pool is in the pre-money, the usual term. Moved after the round, you each hold 28.83 % instead of 28.30 %.[assumption]The note's interest runs to 15 December 2026: $54,619 converts, not $50,000.
Before you sign: have your lawyer confirm whether the term sheet's 10 % pool is pre- or post-money, and that the early angel's SAFE really is the pre-money form; that is what converts it at $0.46 rather than at its post-money equivalent.
How it's checked
Admitted against plain Claude Code: on held-out evals written blind from its description, two judges preferred it in 2 of 4 and 4 of 4 pairs, and it met 79% of their checks, against 75% without it (RFC-0078). How skills are checked
21 assertions across 3 acceptance evals, and 7 trigger queries. Every skill's checks
What the output must do
When it should and shouldn't activate
Should activate:
- How much of my company will I own after this Series A?
- Model our three SAFEs converting into the seed round
- Compare founder dilution at a $12M and a $16M pre-money
- How much have we given away in SAFEs so far?
Should leave to another skill:
- Review this SAFE agreement before I sign it
- Build a three-statement financial model for our seed deck
- Write the business case for hiring two engineers
Source
SKILL.md · the whole folder on GitHub.