When a company prints new shares, every existing slice of the pie gets thinner. Enter shares outstanding, new shares issued and optionally your holding and net income to see exactly how much thinner.
Answer first: dilution is what happens to existing shareholders when a company issues new shares — through a secondary offering, employee stock compensation, convertible debt, or an acquisition paid in stock. Your share count never changes, but the total pie grows, so your percentage of the company shrinks, and each share’s claim on earnings shrinks with it. Issue 10 million new shares on top of 100 million and every existing holder is diluted by 10 ÷ 110 ≈ 9.1%.
Dilution % = new shares ÷ (old shares + new shares)
Example: 100M shares outstanding, 10M new shares issued → 9.09% dilution. EPS on $500M of net income falls from $5.00 to $4.55 even though profit did not change.
| Source | Typical size | Warning sign? |
|---|---|---|
| Stock-based compensation | 1–5% per year at many tech firms | Normal, but it compounds relentlessly |
| Secondary offering | 5–20% at once | Depends what the cash buys |
| Convertible notes converting | Varies | Pre-announced — read the filings |
| Stock-funded acquisitions | Can exceed 20% | Judge the deal, not just the dilution |
New shares are how young companies fund growth they cannot yet pay for — and some of the best investments in history diluted holders repeatedly while the business value grew far faster than the share count. The question is never “was there dilution?” but “did each remaining slice get more valuable?” A biotech raising cash to fund a successful trial dilutes you into a bigger prize. A struggling company issuing shares just to pay bills dilutes you into a slower sinking.
The opposite move exists too: buybacks retire shares and concentrate ownership, which is why EPS can rise even in years when total profit is flat. Watching the fully diluted share count over five or ten years — disclosed in every annual report — tells you which direction management leans, and it is one of the most underrated numbers in a filing.
Reality check: announced dilution percentages usually use basic shares outstanding; options, warrants, RSUs and convertibles waiting in the wings mean the fully diluted number is bigger. Companies report both — the gap between them is the dilution already queued up. Educational tool only — not financial advice.
Related tools: the EPS calculator (basic vs diluted), market cap calculator, and stock split calculator — note that a split changes the share count without dilution, since every holder’s count is multiplied equally. Background: what is a stock buyback and what is a stock.
Last updated July 2, 2026 · Written by Mustafa Bilgic. Educational only — not financial advice.
Divide the new shares issued by the total shares after issuance. Issuing 10M new shares on 100M outstanding dilutes existing holders by 10 ÷ 110 ≈ 9.09%.
No — you keep every share you own. Dilution reduces your percentage ownership and each share's claim on earnings, because the total number of shares grows.
Not necessarily. If the capital raised grows the business faster than the share count grows, each diluted share can end up more valuable. Dilution to fund losses is the damaging kind.
No. A split multiplies every shareholder's count equally, so ownership percentages are unchanged. Dilution issues shares to someone else, shrinking your percentage.
Basic counts shares currently outstanding; diluted adds shares that would exist if all options, warrants, RSUs and convertibles were exercised. The diluted figure shows dilution already committed.