Equity Dilution Calculator

Use this Equity Dilution Calculator to get fast and reliable results with a clear workflow and practical guidance.

100% Client-Side Processing

All processing happens in your browser. Your input is not uploaded to a server.

Current cap table

Use fully-diluted shares if you want a fully-diluted ownership estimate.

Your ownership input

Your pre-money ownership percentage

Dilution event

New shares created in this round

Used to estimate implied pre/post money and pro-rata cost

For an option pool increase or other reserve created at the same time

Enter your cap table and dilution event details above to see the results.

Assumptions:

  • Dilution assumes you do not participate in the new issuance (no pro-rata exercise).
  • Pro-rata shares to maintain ownership are calculated as: your shares × (new shares ÷ pre-money shares).
  • Implied valuations use the price per share multiplied by share counts; actual valuations may differ based on liquidation preferences, participation rights, and other terms.
  • Additional reserved shares (e.g., option pool) are treated as part of the post-money share count and dilute all existing holders proportionally.
  • This calculator does not model SAFEs, convertible notes, or instruments with discounts/caps—those require separate conversion calculations.

What is this tool?

Equity Dilution Calculator helps you complete this task quickly and consistently without switching between multiple apps.

It is designed for day-to-day use with clear inputs, practical outputs, and a straightforward user experience.

How it works

  • Enter or paste your input data in the fields provided.
  • Adjust options to match your use case and preferred output format.
  • Review the generated result and copy it for your workflow.

Best practices

  • Use realistic sample data first to verify your settings.
  • Double-check critical values before sharing or publishing results.
  • Save final outputs in your project docs for repeatable workflows.

Frequently asked questions

Is this tool free to use?

Yes. You can use this tool directly in your browser at no cost.

Is my data private?

Yes. Inputs are processed locally in your browser and are not sent to a server.

Can I use this on mobile?

Yes. The tool is designed to work on both desktop and mobile browsers.

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