Equity dilution calculator
How much will new shares dilute ownership?
Model a stock offering or conversion. See the ownership impact first, then compare the price and proceeds.
Offering assumptions
Use whole shares. Prices add issuance value and the offering discount; leave them blank to calculate ownership only.
Ownership dilution formula
2,500,000 ÷ 12,500,000 × 100 = 20%
Assumes existing holders keep the same number of shares. Ownership dilution does not predict a stock-price move.
Ownership dilution
20%
80% retained ownership for existing holders, relative to their previous stake.
- Post-issuance shares
- 12,500,000
- Issuance value (before fees)
- $2,250,000
- Offering discount
- 25%
Issuance value is gross proceeds for a cash offering; conversions may raise no new cash. Discount compares offering price with current share price. Unavailable results appear as —.
Stock dilution example: a 2.5 million-share offering
1. Enter the offering terms
Start with 10 million existing shares, 2.5 million new shares, a $1.20 market price, and a $0.90 offering price. These are the calculator's starting inputs.
2. Calculate the ownership impact
Post-issuance shares are 12.5 million. Divide 2.5 million by 12.5 million to get 20% ownership dilution. An unchanged 1% holding becomes 0.8% of the company.
3. Separate dilution from discount
The offering raises $2.25 million before fees at a 25% discount to the $1.20 market price. The 20% ownership dilution does not predict a 20% stock-price decline.
The example assumes the existing holder keeps the same number of shares and excludes fees and other share changes. For a public stock, check the outstanding share count and any additional warrants or conversion terms before entering your scenario.
Equity dilution FAQ
How do you calculate share dilution?
Divide the newly issued shares by the total shares outstanding after the issuance. If a company has 10 million shares and issues 2.5 million more, the new shares represent 20% of the post-issuance share count.
Is dilution always bad?
Not always. Dilution can fund growth, acquisitions, debt reduction, or survival. It becomes more concerning when the company raises at a steep discount, has weak cash runway, or has repeated financing overhang.
What should public-market traders check after calculating dilution?
Check the SEC filings behind the issuance: S-1, S-3, 424B5, 8-K, ATM agreement, warrant terms, conversion price, resale registration, and remaining shelf capacity.
Check the filing behind your assumptions
Look up a ticker to research outstanding shares, financing terms, warrants, and conversions before modeling an issuance.
Explore SEC filing analysis →Search opens a ticker report and does not populate this calculator. Full dilution reports require a subscription.