Startup Cap Table Calculator
Estimate dilution, ownership percentages, and post-money share counts after a funding round.
Tip: This model assumes a simple priced round and does not include SAFEs, notes, liquidation preferences, or multiple share classes.
Why a cap table matters
A capitalization table (cap table) is the ownership map of your company. It tracks who owns how many shares, what percentage of the business each stakeholder controls, and how those percentages change over time. Early on, many teams ignore this and focus on product and growth. That’s understandable—but expensive mistakes happen when founders don’t model dilution before a round.
A good cap table process helps you answer practical questions fast: How much will founders be diluted? Is the option pool large enough for planned hires? How much ownership does a new investor receive at a given valuation? This calculator gives you a clean starting point for those decisions.
What this cap table calculator does
This tool calculates a single financing event using a straightforward structure. You enter current shares, valuation, and investment size. The calculator then estimates:
- Price per share based on the pre-money valuation
- New shares issued to the investor
- Optional top-up required to reach a target post-money option pool
- Post-money ownership percentages for founders, option pool, other holders, and new investors
- Founder dilution from pre-round to post-round
Input guide
1) Founder shares
This is the total common stock currently owned by founders. If there are multiple founders, combine their shares for this input.
2) Existing option pool
Use the currently authorized and unallocated employee option shares. If your board plans to expand this pool as part of the round, the target pool input will model that increase.
3) Other existing shares
Include advisor grants, early angels, or any other common-equivalent shares already on the cap table.
4) Pre-money valuation and new investment
The pre-money valuation sets the implied price per share for the round. Dividing investment by that price gives investor shares issued in the transaction.
5) Target post-money option pool
Investors often request an option pool percentage after financing to support hiring. If your current pool is below target, this calculator adds shares to reach the desired level.
How to interpret dilution correctly
Dilution is not automatically bad. If new capital increases the value of the company significantly, a smaller percentage of a much larger business can still be a major win. The key is to understand the tradeoff: capital today versus ownership tomorrow.
Two practical checks you should run before accepting term sheets:
- Scenario test: Model conservative, base, and upside valuation outcomes for your next round.
- Hiring plan test: Ensure your option pool can support planned hiring through the next milestone.
Common cap table mistakes founders make
- Not modeling pool refreshes: Option pool expansion can dilute founders materially.
- Ignoring convertible instruments: SAFEs and notes can convert into substantial ownership.
- Over-optimizing early valuation: A valuation that is too aggressive can hurt future fundraising.
- No board-level version control: Cap table files should have one source of truth and clear review ownership.
Practical fundraising advice
Raise enough for milestones, not maximum dilution tolerance
The right round size is usually the amount needed to achieve clear milestones before your next institutional financing, with buffer for delays. Under-raising can force a difficult bridge round. Over-raising too early may produce inefficient spend and misaligned expectations.
Keep your model simple first, then add complexity
Start with this simple structure to get directional answers quickly. Then layer in classes of stock, liquidation preferences, SAFEs, vesting schedules, and pro-rata rights in a dedicated legal-grade model.
Final thoughts
A cap table is more than an accounting artifact—it’s a strategy tool. Use it before every major financing, hiring plan, or equity grant policy change. The founders who consistently model ownership outcomes are often the ones who retain flexibility and avoid preventable surprises.