How to Build a Cap Table for Your Startup

You raise a round, hire your first two engineers, bring on an advisor, and six months later someone asks a simple question: who actually owns this company? If you can't answer that in 30 seconds with a clean document, you have a problem. That document is your cap table, and most first-time founders either ignore it until an investor asks for it or build one so messy it costs them later. Cleaning up a broken cap table before a financing can delay the round by weeks and rack up legal fees that run into the tens of thousands. So let's build one the right way, from zero, before it matters.

What is a cap table, exactly?

A cap table (short for capitalization table) is a record of who owns what in your company. It lists every shareholder, how many shares they hold, what percentage of the company that represents, and what type of security it is.

Think of it as the answer to "if we sold the company tomorrow, who gets paid and how much?" In the earliest days it might be two founders splitting 10 million shares. By Series A it tracks founders, employees with options, angel investors, a venture fund, and a SAFE or two that converted into equity. The table grows every time you issue stock, grant options, or take money.

Here's the thing. A cap table isn't a legal filing. It's a working document you maintain, and its only job is to be accurate. An accurate cap table builds trust with investors. A sloppy one signals that you don't have your house in order, and that follows you into every negotiation.

Why does your cap table matter before you raise?

Your cap table matters before you raise because investors read it as a signal of how you run the company. A clean, well-modeled cap table tells them you understand dilution, you've planned for an option pool, and you won't surprise them with hidden agreements later.

There's a real cost to getting this wrong. Errors like unsigned stock agreements, miscalculated ownership, or missed filings can delay funding by 4 to 8 weeks and add meaningful legal expense during diligence. One analysis put the average cost of serious cap table mistakes at over $2 million when they trigger repricing or disputes. That's not a number you want attached to your seed round.

It also matters for you personally. Founders who don't model dilution end up shocked when they realize how little they own after a couple of rounds. The median founder gives up roughly 19% in a seed round and another 20% to 30% at Series A. Run that math across three rounds and your starting 50% can drop below 20% fast. You can't negotiate well against a process you don't understand.

What goes on a cap table?

A cap table lists every security the company has issued and who holds it. At minimum, each row shows the holder's name, the security type, the number of shares or units, and the resulting ownership percentage on a fully diluted basis.

The main categories you'll track:

• Common stock. This is what founders and most early employees hold. Founders usually buy their shares for a fraction of a cent at incorporation.
• Preferred stock. This is what venture investors get. It comes with extra rights like liquidation preferences, which is why it sits in its own bucket.
• Options and the option pool. Shares reserved for employees and advisors, granted over time with vesting. The reserved-but-unissued portion still counts.
• Convertible instruments. SAFEs and convertible notes that haven't turned into equity yet. These convert at a future round, and you need to model what they become.
• Warrants. Less common early on, but track them if a lender or partner holds any.

One distinction trips up almost everyone: authorized versus issued versus fully diluted. Authorized shares are the maximum your charter allows you to create. Issued shares are what's actually been handed out. Fully diluted shares include everything outstanding plus all options, warrants, and convertibles as if they all existed today. Investors always negotiate ownership on a fully diluted basis. If you quote someone an issued-shares percentage, you're describing a company that doesn't really exist.

How do you build a cap table from scratch?

You build a cap table by starting with founder shares at incorporation and adding a new row every time ownership changes. The goal is one source of truth that you update the same day anything happens, not a file you reconstruct in a panic before a meeting.

Here's a practical sequence.

First, set your total share count at incorporation. Most startups authorize 10 million shares and issue the founder shares out of that. The exact number is arbitrary. What matters is the split. Two equal cofounders might each take 4 million shares, leaving room for a pool and future issuances.

Second, record the founder grants with the details that actually matter: number of shares, price paid, purchase date, and vesting schedule. The standard is four-year vesting with a one-year cliff. Write down the vesting start date, because it drives a tax filing we'll get to in a minute.

Third, carve out your option pool as its own line, even before you've hired anyone. Reserving the pool early makes your fully diluted math honest from day one.

Fourth, add every subsequent event as a new entry. New hire gets options? New row. Angel writes a $25,000 check on a SAFE? New row, flagged as a convertible. Advisor gets 0.5%? New row. Date and document each one.

Fifth, build a simple dilution model alongside the table. This is where you answer "what happens to my ownership if I raise $1.5 million at a $8 million post-money valuation?" You don't need fancy software for this part. A spreadsheet works, and tools like Foundra can help first-time founders model the financial side of a raise (what different round sizes do to ownership and runway) before you ever talk to an investor. You can find planning tools for this at foundra.ai/tools/. The point is to see the dilution before you sign it, not after.

How does dilution work across funding rounds?

Dilution works by issuing new shares to investors, which shrinks everyone else's percentage even though the number of shares you own stays the same. You're trading a smaller slice of a (hopefully) much bigger pie.

Walk through a simplified example. Say two cofounders each own 50% of a company with 8 million shares issued, plus a 2 million share option pool, for 10 million fully diluted. You raise a seed round where the investor gets 20%. To give them 20%, the company issues new shares, and after the round each founder's stake drops from 50% to around 40%. Nobody took anything from you. The denominator just got bigger.

Now do it again at Series A, where investors take another 25% and you expand the option pool. Each founder might land somewhere near 28% to 30%. This is normal. Across the whole journey, expect roughly 20% to 25% dilution per priced round, with seed often in the high teens to about 20% and Series A in the 20% to 30% range.

Two things founders miss. SAFEs and notes from earlier convert at the priced round, and that conversion dilutes you too, sometimes more than you expected if you raised a lot on uncapped or high-cap instruments. And the option pool refresh that investors request usually comes out of the pre-money valuation, meaning you absorb that dilution, not the new investor. Model both, or the headline terms will lie to you.

What about the option pool, and how big should it be?

Your option pool is the chunk of equity reserved for future employees and advisors, and it typically lands between 10% and 15% at the seed stage. Investors will push for a pool to be in place before they invest so their own stake doesn't get diluted by your future hires.

The data is worth knowing because there's a gap between what gets asked for and what's actually used. The median seed-stage option pool sits around 11.8%, with top-quartile companies closer to 16%. Investors sometimes ask for a "standard" 20% pool, but that 20% figure is often a negotiating move that lowers their effective price per share, since the pool comes out of your pre-money. Most startups only use 60% to 70% of their pool before the next round, which means an oversized pool is just extra dilution you handed yourself for no reason.

So size it to your actual hiring plan over the next 12 to 18 months, not to a round number. If you plan to hire four people and one advisor, build the pool from those grant sizes and add a small buffer. Then you can push back when an investor asks for more than you need.

Should you use a spreadsheet or cap table software?

Use a spreadsheet when you're pre-funding with a handful of shareholders, and move to dedicated software once you've raised money or started granting options to employees. The crossover point is usually your first priced round or your fifth or sixth stakeholder.

A spreadsheet is free and flexible, and for two founders and an advisor it's plenty. The risk is that spreadsheets break quietly. A formula error or a forgotten SAFE doesn't announce itself, and you find it during diligence at the worst possible moment.

Once real money and options are involved, software earns its keep because it ties the cap table to the underlying legal documents and handles things like 409A valuations and option grant tracking. A few common options for early-stage founders:

• Carta Launch is free for early companies with up to 25 stakeholders and under $1 million raised, which covers most pre-seed setups.
• Pulley offers a free tier and scales up to around $120 a month, and it's popular with accelerator-backed founders.
• Cake Equity is well-rated for teams scaling headcount, and founders switching from pricier platforms report meaningful savings.

The tool matters less than the habit. Whatever you pick, update it the day something changes and keep the signed documents attached. A cap table is only worth as much as its accuracy.

What are the most common cap table mistakes?

The most common cap table mistakes are missing the 83(b) election deadline, confusing share types, and letting the document fall out of date. Each one is cheap to avoid and expensive to fix.

The 83(b) election is the big one. When you buy founder stock subject to vesting, you have 30 days from the purchase or transfer date to file an 83(b) election with the IRS. File it, and you're taxed on the tiny value of your shares today. Miss it, and you can owe tax as your shares vest and appreciate. The horror story is real: a founder with a million shares that grow from a tenth of a cent to $5 could face millions in taxable income with no liquidity to pay it. The clock starts at the transfer date (usually board approval), not when you sign, and there's no fixing a missed deadline.

The second mistake is mixing up authorized, issued, and fully diluted shares, which leads to mispriced grants and broken promises to hires. Quote ownership on a fully diluted basis, every time.

The rest are blocking and tackling. Unsigned stock purchase agreements. Verbal equity promises with no paper. Option grants approved by nobody. Forgetting to record a SAFE. None of these feel urgent in the moment, and all of them surface during diligence. Keep a clean stock ledger, attach the signed documents, and update the table the same day. Boring discipline beats a panicked cleanup.

Key takeaways

• A cap table records who owns what in your company, and its only job is to be accurate. Investors read a clean one as a sign you run a tight ship.
• Always think in fully diluted terms, which include options and convertibles as if they existed today, not just issued shares.
• Expect roughly 20% to 25% dilution per priced round. The median founder gives up around 19% at seed and 20% to 30% at Series A.
• Size your option pool (usually 10% to 15% at seed) to your real hiring plan, not to an investor's round-number ask. Most pools are only 60% to 70% used.
• File your 83(b) election within 30 days of buying vesting stock. There's no second chance.
• Start in a spreadsheet, then move to a tool like Carta Launch, Pulley, or Cake Equity once you raise or grant options. Model dilution before you sign, not after.

FAQ

What is a cap table in simple terms?
It's a list of everyone who owns a piece of your company, how much they own, and what kind of ownership it is. It answers "who gets what if we sell or raise money."

Do I need a cap table before I raise money?
Yes. Investors expect a clean, fully diluted cap table during diligence, and modeling your dilution beforehand is how you negotiate well. A messy one can delay a round by 4 to 8 weeks.

What's the difference between issued and fully diluted shares?
Issued shares are what's actually been handed out. Fully diluted shares include everything outstanding plus all options, warrants, and convertibles as if they existed today. Investors negotiate on the fully diluted number.

How big should my option pool be?
At seed, most pools run 10% to 15%, with a median near 12%. Size it to your hiring plan over the next 12 to 18 months rather than accepting a default 20% ask, since unused pool is just extra dilution.

When do I need cap table software instead of a spreadsheet?
Switch once you raise a priced round or start granting employee options, usually around your fifth or sixth stakeholder. Free tiers like Carta Launch cover most pre-seed companies.

What is an 83(b) election and why does it matter?
It's a tax filing you make within 30 days of buying vesting founder stock. Filing it lets you pay tax on the tiny value today instead of on the appreciated value as shares vest. Missing the deadline can create a large, avoidable tax bill.