ESOP size seed round: should you carve 10%, 15%, or 20%?

At seed, the median option pool sits around 12% to 14% of fully diluted equity, per Carta 2025 and 2026 data. Sizing above that pushes dilution onto founders through the option pool shuffle. The right number is whatever covers your 12-month hiring plan plus a small buffer, nothing more.

Most founders let lead counsel set the ESOP size seed round figure at 15% or 20% without pushing back. That one decision can move 5 percentage points of ownership from your cap table to the option pool, a line item you pay for but investors don't. Here's the math, the benchmark, and the exact pushback script to use when a term sheet asks for a 20% carve.

How big should the option pool seed benchmark be?

The seed median lands between 12% and 14% of fully diluted equity, not 20%.

Carta's 2026 Founder Ownership Report pegs the median seed-stage employee pool at 12.1% of equity. Carta's guide to vesting and equity schedules puts the figure at around 13.5%. Both numbers sit meaningfully below the 15% to 20% ask that shows up on most first-round term sheets.

Lead with the 12% to 14% range as your anchor. That's where the market actually lives.

The option pool shuffle, with the math

The option pool shuffle is the practice of carving the new or expanded pool pre-money, so founders absorb 100% of the resulting dilution while the investor's ownership is unchanged.

Worked example. You raise $2M at a $10M post-money valuation. The investor takes 20%. Your lead asks for a 20% post-closing pool, up from your current 10%.

Case A: 15% post-money pool, carved pre-money
  Investor:     20%
  Option pool:  15%
  Founders:     65%

Case B: 20% post-money pool, carved pre-money
  Investor:     20%   (unchanged)
  Option pool:  20%
  Founders:     60%   (-5 percentage points)

Moving the ask from 15% to 20% pre-money does not cost the investor a single share. It costs you 5% of the company on a $10M post-money, roughly $500,000 of nominal value at the closing cap.

If the pool is carved post-money instead, the investor pays their proportional share (20%) of the expansion, and founders pay the remaining 80%. For a 5 pp expansion, that means founders give up 4 pp instead of 5 pp. It's a smaller win than right-sizing the pool itself, but it's the fallback ask when the lead won't come down on size.

Sizing the employee option pool from a hiring plan

Don't argue percentages with your lead. Argue a hiring plan.

Index Ventures shows that a typical US seed-stage team of ten employees absorbs around 5% of fully diluted equity in option grants. Cooley's Negotiating the Option Pool confirms that presenting a bottoms-up option budget tied to a specific hiring plan is the most reliable way to get investors to accept a smaller pool.

Build the spreadsheet before the term sheet arrives:

• Role list: every hire you plan to make in the next 12 to 15 months, with title and seniority.
• Grant per role: senior engineer 0.5 to 1.0%, staff engineer 1.0 to 1.5%, VP 2 to 4%. The first ten employees typically land at ~5% in aggregate per Index.
• Buffer: 1 to 2% for unplanned senior hires and refreshers.
• Total needed: sum of grants plus buffer. That is the number you ask for.

If your hiring plan justifies 13%, ask for 13%. If it justifies 11%, ask for 11%. Either way you arrive at the meeting with a defensible number instead of a vibe.

The ESOP seed round negotiation script

Cite a plan, not a benchmark, when the term sheet lands with a 15%+ pre-money carve.

Use this language verbatim with your lead counsel:

"Our bottoms-up hiring plan for the next 12 months supports a [X]% pool post-closing. I've attached the role list and grant sizes. We'd like to size the new pool at [X]%, and we'd like any top-up beyond that to be shared between founders and investors post-money."

Three things this script does. It cites a plan, which Cooley's guide says is the thing that moves investors off default asks. It pre-commits to a number, forcing the investor to rebut your plan rather than float a higher benchmark. And it separates two asks (pool size, then pre vs post-money allocation), so you can concede on one without losing the other.

When the investor counters with "we need room for unexpected hires," point out that option pools recycle as employees leave, and any shortfall can be topped up at the Series A. You don't need to pre-fund hires you haven't decided on.

Why this compounds. Median founder ownership drops from ~56% at seed to ~36% at Series A, and 2025 median Series A dilution sat at ~20.5%. An oversized seed pool carries into the Series A cap table, and the Series A lead will still ask for a top-up on top of it. Every point you give up at seed is a point you give up twice.

FAQ

How big should an ESOP be at seed? The median seed option pool is between 12% and 14% of fully diluted equity per 2025 and 2026 Carta data. Size yours from a bottoms-up 12-month hiring plan rather than accepting the lead's default number. A 10-engineer seed team typically absorbs around 5% in grants, so a pool of 11 to 13% with a small buffer is reasonable for most seed rounds.

What's the option pool shuffle? The option pool shuffle is when the lead investor requires the new or expanded option pool to sit pre-money on the cap table, which means founders alone pay for the dilution while the investor's ownership percentage is unaffected. Moving a 10% pool to 15% or 20% pre-money can shift 5 to 10 percentage points of ownership from founders to the pool.

Who pays for the option pool expansion? If the pool is carved pre-money (the default ask), founders pay 100% of the dilution. If it's carved post-money, founders and investors share it pro rata, so on a 20% round the investor bears 20% of the expansion and founders bear 80%. Fighting for post-money allocation is the standard fallback when you can't shrink the pool itself.

Is 20% option pool too much? Yes for most seed rounds. The 2026 Carta median sits at 12.1%, and a 20% pool requires a hiring plan that grants out nearly twice the typical seed spend, usually involving a named executive hire like a VP Engineering or COO at 3 to 5%. Without that specific role in your plan, 20% is padding that shifts ownership from founders to the option pool.

How do I negotiate the option pool on a term sheet? Come to the call with a bottoms-up hiring plan that lists every role, grant size, and a small buffer. Ask for the pool size your plan supports, and ask for any top-up beyond that to be carved post-money so the investor shares the dilution. Point to option recycling as the reason you don't need to pre-fund unplanned hires.