Stock Dilution
Calculator
Calculate the impact of new share issuance on existing
shareholder ownership percentage, earnings per share
and share value. Free, instant and no login required.
Stock Dilution Calculator — WSC Free Online Tools
Finance
10.00%
8.00%
−2.00% ownership
Always
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Before & After View
Dilution Included
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📉 Stock Dilution Calculator
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shares
shares
5.00
500,000
shares
4.50
1,000,000
10.00%
$500,000
$0.50
1,250,000
8.00%
$500,000
$0.40
−2.00%
−$0.10
−20.00%
| Shareholder | Shares | Before % | After % | Change |
|---|---|---|---|---|
| You | 100,000 | 10.00% | 8.00% | −2.00% |
| Other existing shareholders | 900,000 | 90.00% | 72.00% | −18.00% |
| New shareholders | 250,000 | — | 20.00% | +20.00% |
| Total | 1,250,000 | 100.00% | 100.00% | — |
illustrative and educational purposes only. Share values and ownership
percentages shown are based on the inputs provided. This is not financial
or investment advice. Consult a qualified financial adviser before making
investment decisions.
What Is Stock Dilution?
Stock dilution occurs when a company issues new shares, increasing the total
number of shares outstanding. This reduces the ownership percentage of existing
shareholders — even though the number of shares they hold stays the same.
Dilution can happen through new share issuances for fundraising, employee stock
option plans (ESOPs), convertible notes converting to equity, stock-based
acquisitions or rights issues.
How Is Dilution Calculated?
The ownership percentage before and after dilution is calculated using the
following formulas:
After ownership % = (Your shares ÷ Total shares after) × 100
Dilution % = Before ownership % − After ownership %
Total shares after = Total shares before + New shares issued
What Is EPS Dilution?
Earnings per share (EPS) dilution occurs when new shares are issued without
a proportional increase in net earnings. More shares dividing the same earnings
means each share represents a smaller portion of the company’s profit.
EPS after = Net earnings ÷ Shares after
EPS dilution = EPS before − EPS after
Key Concepts
Ownership Dilution
Your percentage ownership of the company decreases when new shares are
issued to others — even if the company’s total value increases.
Value Dilution
If new shares are issued below the current market price, the average
value per share decreases — reducing the value of existing holdings.
Anti-Dilution Rights
Some investors hold anti-dilution provisions that adjust their share
count or conversion ratio to protect against dilutive issuances.
Fully Diluted Shares
The fully diluted share count includes all shares that could exist if
all options, warrants and convertible instruments were exercised.
When Does Dilution Happen?
Common dilutive events include: raising capital through a new share issue,
employee stock option plans (ESOPs) vesting and being exercised, convertible
notes converting to equity at a discount, rights issues offered to existing
shareholders and stock-based acquisitions where shares are issued as
consideration.
Not all dilution is negative — if the capital raised is deployed effectively
and grows the company’s earnings, the per-share value can increase even as
the ownership percentage decreases.