Share Dilution Calculator

Add existing shares and new shares to get the post-issue total. Divide new shares by that total and multiply by 100. This is the relative percentage decrease in every unchanged existing holding's ownership.

Dilution percentage equals new shares divided by existing shares plus new shares. In symbols: N ÷ (E + N) × 100, where E is existing shares outstanding and N is newly issued shares.

For a simple completed issuance, add current shares outstanding and new shares issued. This page calls that the post-issue share count; it is not automatically the same as a fully diluted accounting or cap-table count.

An unchanged shareholder retains 90% of the ownership percentage held before the issue. If the holder owned 2%, the new percentage would be 1.8%. It does not mean the holder lost 10 percentage points.

They use different denominators. Share-count increase divides new shares by old shares. Ownership dilution divides new shares by the larger post-issue total. Adding 100 to 900 raises shares 11.11% but dilutes ownership 10%.

The post-issue count stays equal to the current count, existing holders retain 100% of their prior ownership percentage, and dilution is zero.

Divide your current shares by the company's current shares outstanding and multiply by 100. The optional holding must be no greater than the company total.

If you buy none of the new issue, divide the same personal share count by total shares after issuance. Your share count is unchanged, but the denominator is larger.

It is ownership before minus ownership after. A fall from 2.00% to 1.80% is a decrease of 0.20 percentage points and a relative dilution of 10%.

Multiply your old ownership fraction by the number of new shares. Equivalently, multiply your holding by new shares divided by existing shares. This assumes you are permitted and able to participate pro rata.

No mechanical conclusion follows from the share count alone. Ownership percentage falls for a non-participating holder, but stake value also depends on what the company receives or accomplishes and how its total value changes.

Not necessarily. Market price reflects expectations about proceeds, financing terms, growth, risk, supply, demand and many other facts. This calculator does not predict a price reaction.

Enter shares outstanding. The SEC defines authorized shares as the maximum permitted under organizational documents. Authorized but unissued shares do not enter the ownership denominator merely because they are available.

No. Issued shares can include treasury shares held by the company, while outstanding shares are held by investors. Use the transaction disclosure's outstanding count and keep definitions consistent across both inputs.

Check the company's latest 10-K, 10-Q, 8-K, registration statement, prospectus or offering supplement on SEC EDGAR. Confirm the dates and whether the figures are basic, issued, outstanding or fully diluted.

It is a defined scenario that may include potential common shares from options, warrants, RSUs, convertibles or other instruments. The included instruments and accounting treatment depend on the context; disclose the convention rather than assuming one universal count.

Enter shares that you explicitly assume will become part of the denominator as new shares. Do not mix a basic current count with an undocumented fully diluted new count. Exercise prices and treasury-stock accounting are outside this tool.

Investor.gov explains that conversion can create new common shares, reducing proportional ownership and earnings per share. The exact number depends on the security's conversion terms, so calculate that separately before entering it here.

A proportional stock split does not dilute ownership because every holder and the total share count change by the same ratio. Investor.gov explicitly distinguishes a split from issuing new shares.

Only when the classes have equivalent economic ownership for the question being asked and the filing itself combines them that way. Different voting, conversion or economic rights may require a cap-table analysis rather than this simple denominator.

No. Offering documents also use dilution to describe the difference between an offering price and post-offering net tangible book value per share. That calculation needs assets, liabilities, proceeds and costs, which are not inputs here.

No. The SEC distinguishes basic EPS from diluted EPS, which may include common-stock equivalents and accounting adjustments. This page calculates proportional ownership from entered share counts only.

No. It includes only the new-share number you enter. Unissued options, RSUs, warrants, convertibles, future offerings, acquisitions and compensation plans can add more shares later.

Yes. Copy link puts the entered share counts into the URL. The link is created in your browser and opens with the same result. Anyone who receives it can read those values.

No. All arithmetic runs locally in your browser. The company share counts and optional personal holding are not submitted, saved, connected to a brokerage account or included in analytics.

No. It is transparent ownership arithmetic using numbers you supply. It does not assess the company, financing terms, valuation, expected return, voting control, tax consequences or suitability.