An ESOP pool is one of the most important decisions a founder makes about their cap table, and it is often made hastily — a number picked because an investor suggested it, or copied from another company without much thought. Getting the pool right matters, because it directly affects how much equity is available to attract talent, how much founders are diluted, and how the company's ownership evolves across funding rounds. This guide walks through how to think about designing an ESOP pool deliberately.
What an ESOP pool is
An ESOP pool — sometimes called an option pool or equity incentive pool — is a portion of the company's equity set aside specifically to grant to employees as stock options. Instead of issuing equity ad hoc each time you want to give someone options, you carve out a defined percentage of the company up front, and grants to employees draw down from that reserved pool.
The pool is expressed as a percentage of the company's fully diluted share capital. So a "10% ESOP pool" means 10% of the company, on a fully diluted basis, is reserved for employee equity.
How big should the pool be?
This is the first question, and the honest answer is that it depends on the company's stage, hiring plans, and the norms of its market — but there are useful anchors.
Early-stage startups commonly set aside somewhere in the region of 10% to 15% of the company for their ESOP pool, though this varies. The right size is really a function of how many people you plan to hire before the next funding round and how much equity each of those hires will expect. A company planning to hire several senior leaders — who command larger grants — needs a bigger pool than one hiring mostly junior staff.
The mistake at both ends is worth avoiding. Too small a pool, and you run out of equity to offer mid-way through your hiring, forcing an awkward and dilutive top-up at a bad time. Too large a pool, and you dilute the founders more than necessary, since unallocated pool sits on the cap table as potential dilution. The goal is a pool sized to your actual hiring plan through to the next round, with a sensible buffer.
How the pool dilutes founders
Here is a subtlety that catches many founders out, particularly around funding rounds. When investors require a pool to be created or expanded as a condition of an investment, the way it is structured determines who bears the dilution.
If the pool is created or topped up before the investment closes — out of the pre-money valuation — the dilution falls on the existing shareholders, primarily the founders. If it is created after, it dilutes everyone including the new investors. In practice, investors typically require the pool to be sized and put in place pre-money, which means the founders absorb the dilution. This is a standard but often under-appreciated dynamic: the "10% pool" an investor asks for in a term sheet is usually 10% that comes out of the founders' ownership, not the round as a whole. Understanding this before negotiating the term sheet is important, because the pool size is effectively a price term.
Refreshing the pool across rounds
An ESOP pool is not set once and forgotten. As the company grows and hires more people across successive funding rounds, the pool typically needs to be replenished — "refreshed" — because grants made to employees draw it down.
At each funding round, there is usually a discussion about topping the pool back up to a target percentage to cover the next phase of hiring. Each refresh is dilutive, so there is a genuine trade-off between keeping a large standing pool (more dilution carried now) and refreshing frequently (repeated smaller dilutions, plus the negotiation each time). Planning the pool with the next round's likely refresh in mind helps avoid surprises. Tracking how much of the pool is granted, vested, and still available is essential to knowing when a refresh is needed.
Allocating grants across the team
Once you have a pool, the question becomes how to allocate it. A few principles help.
Senior and early employees generally receive larger grants, reflecting both their impact and the greater risk they take by joining early. Grant sizes typically step down as the company matures and the equity becomes less risky — an early engineer who joins pre-product-market-fit takes more risk than one who joins after a large funding round, and grant sizes usually reflect that.
Many companies develop a grant framework or banding — defined grant ranges by level and role — to keep allocations consistent and defensible, rather than negotiating every grant from scratch. This also helps with fairness, since ad hoc grants can create awkward disparities between people doing similar work.
It is also worth deciding the vesting terms up front — the standard being a multi-year vest with an initial cliff — and applying them consistently. We cover vesting in detail in a separate guide.
Keeping track of the pool
A pool is only useful if you know its state at any time: how much has been granted, how much of those grants has vested, how much has been forfeited by leavers and returned to the pool, and how much remains available to grant. This is the cap-table discipline that underpins a healthy ESOP programme.
When grants, vesting, forfeitures, and the available balance are tracked loosely — in a spreadsheet updated occasionally — it is easy to lose sight of the true available pool, over-grant, or misstate the fully diluted picture. As the team grows and grants multiply, this gets harder to manage by hand.
Common mistakes in pool design
The recurring errors include:
Sizing the pool by copying another company rather than mapping it to your own hiring plan, ending up too big or too small.
Not understanding that an investor-required pool typically dilutes the founders pre-money, and treating it as a neutral term.
Letting the pool run dry mid-hiring, forcing a poorly-timed dilutive top-up.
Granting inconsistently across the team without a framework, creating unfairness and disputes.
Losing track of how much of the pool is actually available because grants, vesting, and forfeitures are tracked loosely.
Why pool management belongs with your cap table and payroll
An ESOP pool is fundamentally a cap-table object that interacts with hiring (each new grant draws it down), with vesting (which determines what is actually earned), and with payroll and tax (when options are exercised). When the pool lives in a standalone spreadsheet separate from the cap table, the hiring system, and payroll, keeping the available balance accurate and the fully diluted picture correct becomes a manual reconciliation exercise that degrades as the company grows.
When ESOP management, the cap table, hiring, and payroll all sit on a single database, the pool's state is always current — a grant made when hiring someone immediately draws down the available balance, vesting updates what is earned, a leaver's forfeited options return to the pool, and an exercise flows through to payroll and the cap table together. There is no separate spreadsheet to reconcile. This is exactly how Helion is built — ESOP and the cap table live natively alongside hiring and payroll on the same schema, so the pool is always accurately stated and an exercise never falls between two systems. For a founder managing an equity programme as the team scales, that single-source-of-truth design turns pool management from a source of cap-table anxiety into a reliable, always-current view.
This guide gives general information on ESOP pool design for founders and is not legal, tax, or financial advice. Pool sizing, dilution mechanics, and grant structures should be discussed with qualified legal and financial advisors in the context of your specific company and jurisdiction.