KarobarKit
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Startup · Local-first · Beta

Equity Dilution Calculator

Preview post-money ownership and an option-pool scenario from a reconciled starting cap table.

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Trust record

Check the method before you rely on the result

Tier B · Runs locally in this browser
Method
Post-money ownership arithmetic with a post-money option pool and pro-rata dilution of existing holders.
New investor % = investment ÷ post-money; existing holder % = original holder % × remaining post-money ownership.
Sources
2 reviewed references · 1 official
Open the source register
Effective period
Formula-based; no statutory effective period
Last verified
10 August 2026
Review every 90 days
Reviewer status
Named corporate/legal reviewer: external review pending
Privacy
Startup inputs and results stay in this browser. They are not sent to analytics, a backend, a URL or a log, and are not saved by default. These outputs are user-entered scenarios, not recommendations or professional valuations.
Important limitations
  • It does not model share classes, liquidation preferences, convertibles, SAFEs, employee grants or legal approvals.
  • Existing holder percentages must be supplied and reconcile exactly to 100%.

Read all limitationsReport an error

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A quick guide

Use the number with context

The answer is only useful when you know what it includes and what it leaves out.

How to use it

  1. Enter pre-money valuation using the same period and unit as the other inputs.
  2. Enter new investment amount using the same period and unit as the other inputs.
  3. Enter founder ownership before investment using the same period and unit as the other inputs.
  4. Enter existing investor ownership before investment using the same period and unit as the other inputs.
  5. Enter other holder ownership before investment using the same period and unit as the other inputs.
  6. Enter target option pool after investment using the same period and unit as the other inputs.

Formula

New investor % = investment ÷ post-money; existing holder % = original holder % × remaining post-money ownership.

The cap-table preview reconciles to 100% under the stated post-money pool assumption.

Make it concrete

Worked example

₹6 lakh into a ₹24 lakh pre-money company gives a 20% new investor share before the selected option-pool scenario.

Boundaries

What this tool does not assume

Limitations

  • It does not model share classes, liquidation preferences, convertibles, SAFEs, employee grants or legal approvals.
  • Existing holder percentages must be supplied and reconcile exactly to 100%.

Edge cases

  • An option pool that leaves no room for the investor is rejected.
  • A zero or negative valuation is rejected rather than producing a meaningless percentage.

Last reviewed 10 August 2026 · Formula version 1.0

Method & sources

How this result is grounded

The formula is deterministic and runs in your browser. Read the reference below for the method used by this tool.

Questions

Frequently asked

Does this create a cap table?

No. It previews simple ownership percentages from your inputs and does not issue or reserve securities.

Why is the option pool described as post-money?

That makes the dilution convention explicit; other term-sheet conventions can produce different results.

Keep going

Related tools

A related local-first tool for the next step.

Found something that looks wrong? Tell us which tool and version you used.

Source register checked 10 August 2026.