Cap Table Template: Series A and B Guide with Waterfall Math

A cap table is a spreadsheet that tracks who owns what percentage of a company, how ownership changes across financing rounds, and what each stakeholder receives in an exit. A complete SaaS cap table in 2026 handles four specific mechanics most founder-built templates get wrong: SAFE note conversion at the next priced round, option pool refreshes that dilute existing shareholders (not the new investor), pre-money versus post-money valuation math, and exit waterfall distribution with liquidation preferences. Getting these four right is what separates a cap table that holds up in a Series A diligence from one that triggers a rebuild.

What a cap table actually tracks

A cap table — short for capitalization table — is the authoritative record of who owns what in a company. In its simplest form it's a table with three columns: name, share count, and ownership percentage. In practice it's considerably more complex because shares come in classes (common, preferred Seed, preferred Series A, preferred Series B), instruments convert at specific triggers (SAFEs, notes, warrants), pools refresh at specific events (option pool expansions), and exits distribute proceeds through a defined legal waterfall.

A correctly maintained cap table answers four questions instantly: how much of the company does each stakeholder own today, how much will they own after the next round, what they receive in an exit at a given valuation, and what the founders retain across the full fundraising path. A poorly maintained cap table can't answer any of these reliably, which is why VC diligence partners rebuild founder-supplied tables roughly 80% of the time.

The goal of a founder's cap table is not complexity — it's clarity. The right structure separates inputs (what you can change), rounds (what happens at each event), and outputs (ownership at each point in time, exit proceeds at each valuation). A model that mixes these three into one tab becomes unreadable by the Series A.

The four mechanics most templates get wrong

Before building the template, understand the four places founder-built cap tables most commonly break.

SAFE conversion math. A SAFE (Simple Agreement for Future Equity) is not equity until it converts. It converts at the next priced round, and the conversion uses the better of two pricing mechanisms for the SAFE investor: the valuation cap or the discount. If the round happens at a pre-money below the cap, the discount typically applies. If the round happens at a pre-money above the cap, the cap applies. Templates that model SAFEs as equity from day one produce wrong ownership percentages throughout.

Option pool refreshes. When a Series A round includes a refreshed option pool to a target percentage (typically 10-15% post-money), that refresh comes out of the pre-money valuation. In practice this means founders and existing shareholders get diluted twice at the round — once by the new investor, and once by the option pool expansion. The new investor's ownership percentage is calculated after the pool expansion, so they escape the second dilution. Templates that dilute everyone equally understate founder dilution by 2-5 percentage points.

Pre-money versus post-money math. Pre-money valuation is the company's value before the new money hits the bank. Post-money is pre-money + new investment. The investor's ownership is investment / post_money, not investment / pre_money. Templates that calculate investor ownership off the pre-money overstate investor share and understate founder ownership.

Exit waterfall with preferences. Preferred shareholders have liquidation preferences — they get their money back (typically 1×) before common shareholders receive anything. Participation rights let them double-dip: take the preference and share in the remaining common pool. Caps limit how much they can take via participation. Templates without waterfall logic can't answer "how much do founders net in a $50M exit?" — the answer depends on the preference stack.

Getting these four right requires intentional modeling. The rest is mechanical.

Step 1: Structure the founder table

The cap table at company formation is simple. Two or three founders, each with a share count, with a four-year vesting schedule and a one-year cliff. Total shares authorized are typically 10,000,000 — an industry-standard number that makes percentages easy to read.

The initial structure:

The option pool at formation is typically 10% — large enough to cover the first 2-4 hires, small enough that founders retain meaningful ownership.

The key modeling decision: represent the option pool as "Reserved" (not yet issued) so it shows up as potential dilution but doesn't dilute current ownership calculations. When options are granted to employees, they move from Reserved to Issued. When they vest, they remain Issued.

Step 2: Model SAFE notes correctly

A SAFE investor gives the company cash today in exchange for shares that will be issued at the next priced round. The conversion terms typically include either a valuation cap, a discount, or both.

Example: a Seed SAFE investor puts in $1,000,000 with a $10,000,000 valuation cap and a 20% discount. At the Series A, if the priced round happens at $20M pre-money, the SAFE investor's shares are calculated as:

Cap-based conversion price = $10M / current share count
Discount-based conversion price = Series A price × (1 - 20%) = Series A price × 0.8
Actual price = MIN(cap-based, discount-based)
Shares issued to SAFE investor = $1,000,000 / actual price

Because the Series A is above the cap, the cap-based price is lower, so the cap applies. The SAFE investor gets shares priced as if the company were valued at $10M, not $20M — which is the reward for funding earlier.

In Excel this is:

=MIN(SAFE_Cap / Pre_Round_Share_Count, Series_A_PPS * (1 - SAFE_Discount))

Once the conversion price is known, shares issued is just cash divided by price. The SAFE investor joins the cap table as a holder of preferred shares at that point, with their own row.

The common mistake: modeling the SAFE as a fixed ownership percentage from day one. The SAFE investor's ownership is not determined until the Series A — it's a function of what the Series A pre-money actually is. This matters because a higher Series A pre-money means the SAFE investor gets less ownership (they benefit from the cap, but the cap is now a smaller slice of a larger pie).

Step 3: Handle option pool refreshes correctly

The Series A term sheet typically includes a provision: "The option pool shall be refreshed to 10% post-money at the closing of this round." This means the pool, whatever size it is today, gets topped up so that post-round it represents 10% of the fully diluted post-money cap table.

The expensive subtlety: this refresh is typically modeled as coming out of the pre-money valuation. Mechanically, this means the pre-money for purposes of calculating the founders' share is reduced by the value of the new pool.

Example: a Series A round at $20M pre-money, $5M investment. The existing pool is 5% pre-round; the round refreshes to 10% post-money.

Without the pool refresh:

• Series A investor ownership = $5M / $25M = 20%
• Pre-round holders ownership = 80%

With the pool refresh (which comes out of pre-money):

• New pool shares = 10% × post-money fully diluted
• Effective pre-money for founders = $20M − new pool value
• Founders' dilution is higher than the 20% the investor took

In a worked example, a founder pair with 90% pre-round and a 5% pool (95% pre-money founder + pool), after a 20% investor stake and a 10% post-money pool, ends up at about 72% founder + employee ownership — an 18-point drop, of which 20 points is the investor and "negative 2 points" appears to come out of the pool expansion. The arithmetic only closes because the pre-money was effectively reduced.

This is why experienced founders negotiate for "pool before" versus "pool after" and for the specific target percentage. A 5% pool refresh costs half as much dilution as a 10% refresh.

Step 4: Build the exit waterfall

The exit waterfall is how proceeds get distributed when the company is acquired or goes public. The order matters and the preferences stack.

The standard waterfall in order:

1. Debt gets paid first. Any senior debt, convertible notes still outstanding, and bridge loans take proceeds off the top.
2. Preferred liquidation preferences. Each preferred class gets its preference multiple (typically 1×) times its investment, in reverse order (most recent class first). Series B gets paid before Series A, which gets paid before Seed.
3. Participation, if applicable. Some preferred shares are "participating" — they take their preference AND share in the remaining common pool pro rata. This is expensive for founders and is increasingly rare in top-tier rounds.
4. Common stock pro rata. Whatever remains gets distributed to common shareholders (founders and employees) and non-participating preferred converting to common (they convert if common would get more than their preference).
5. Caps adjust outcomes. Some preferred shares have participation caps — they participate up to a multiple (typically 2-3×) and then stop.

The Excel modeling for a waterfall is a set of IF-and-MIN formulas that walk down the preference stack:

Remaining_Proceeds = Exit_Value - Debt
Series_B_Preference = MIN(Remaining_Proceeds, Series_B_Investment × Series_B_Multiple)
Remaining_Proceeds = Remaining_Proceeds - Series_B_Preference

Series_A_Preference = MIN(Remaining_Proceeds, Series_A_Investment × Series_A_Multiple)
Remaining_Proceeds = Remaining_Proceeds - Series_A_Preference

... and so on through the preference stack
Common_Pool = Remaining_Proceeds distributed pro rata to common

The question every founder should be able to answer with this model: "If we exit at $X, what do I net?" The answer changes dramatically based on the preference stack. A founder with 40% ownership and a $50M exit might net anywhere from $5M to $18M depending on the preferences ahead of them.

The 2025 SaaS round sizes and valuations

For calibration, here are the median private SaaS round sizes and valuations as of Q4 2025, sourced from Carta State of Private Markets and Bessemer State of the Cloud 2025:

The ~20% dilution per round is the most consistent pattern in SaaS fundraising. Three rounds of 20% dilution leaves founders at 51% of their pre-Seed ownership; four rounds leaves them at 41%; five rounds at 33%.

This is why cap table planning matters from Day 1. The founder who enters Series A at 80% founder ownership ends up at very different place than one who enters at 65%.

Common mistakes in cap table modeling

Forgetting to include unissued options in dilution calc. Options authorized but not granted still count against founder ownership in any fully diluted calculation. Many templates show "basic" ownership (only issued shares) without the fully diluted view, which understates dilution.

Modeling SAFEs with a single assumed conversion price. SAFEs convert at different prices depending on the next-round valuation. A template should let the user sensitivity-test: "What if the Series A is at $15M pre-money instead of $20M?" and see how SAFE conversion changes.

Ignoring vesting. Founders with 50% ownership on paper may have only 25% vested. A cap table that shows only authorized shares without a vesting schedule misrepresents the actual equity position.

Rounding errors in share counts. Converting percentages to share counts and back introduces rounding. Always track the authoritative share count, not the percentage. A 10,000,000 authorized share structure keeps percentages readable to the tenth of a percent.

No waterfall. Without exit waterfall logic, the cap table tells you ownership but not payoff. A founder selling at $100M with 25% ownership does not necessarily net $25M — preferences may eat 30-40% of that depending on the stack.

Key takeaways

A correct cap table handles four mechanics that most founder-built templates get wrong: SAFE conversion math, option pool refresh dilution, pre- versus post-money calculations, and exit waterfalls with preferences. A template that handles all four lets a founder plan a fundraising path from Seed through Series C and know, within reasonable bounds, what they'll own at each stage and what they'll net in an exit. The single most expensive mistake is misunderstanding who bears the dilution of an option pool refresh — it's founders and existing shareholders, not the new investor.

For a SaaS financial model with a full cap table including SAFE modeling and scenario-switched dilution, see the Meritra SaaS Financial Model. For related fundraising content, see our guides on the Fintech Pitch Deck Template and Rule of 40 benchmarks that investors use to decide what valuation to offer.