Stock Split Calculator

Calculate new share count and price per share after a stock split.

By Konstantin Iakovlev · Updated September 2026 · Source: SEC

$

New Shares

200

New Price/Share

$100.00

Split Details

Before: Shares100
Before: Price$200.00
After: Shares200
After: Price$100.00
Total Value (unchanged)$20,000.00

Use the Stock Split Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.

How It Works

When a company splits its stock, the number of shares you hold rises and the price of each share falls in lockstep, leaving the dollar value of your position untouched. Enter your holdings and the split ratio here and the calculator returns your new share count and adjusted per-share price in a single step. Knowing exactly how the arithmetic shakes out keeps you from misreading split headlines.

The mechanics follow directly from the split ratio. For a ratio of A:B (say 2:1 or 3:1), multiply your original share count by A and divide by B to get the new count; for the price, multiply by B and divide by A. The two adjustments move in opposite directions by design, which is why your total investment value is identical the moment the split takes effect.

None of this creates or destroys wealth. A split slices the same pie into more pieces, so a lower post-split price is not a discount, no matter how it looks on a quote screen. The same logic applies when you read historical charts: a stock that traded at a high level years ago may simply not have been split-adjusted yet, so apply the split ratio before drawing any conclusion about how the price has moved over time.

Example: A 5-for-1 Stock Split

  1. 1 Input: you own 50 shares of a stock trading at $300, and the company announces a 5-for-1 split. Enter 50 shares, $300 and the 5-for-1 ratio.
  2. 2 New share count: 50 × 5 = 250 shares. New price: $300 / 5 = $60 per share.
  3. 3 Position value before and after: 50 × $300 = $15,000 and 250 × $60 = $15,000, which the calculator shows as the unchanged total.
  4. 4 Your cost basis is spread the same way: IRS Publication 550 treats the new shares from a split like identical stock dividends, so the basis of the original 50 shares is divided over all 250. A $300-a-share basis becomes $60 a share.

Source: SEC · Last updated: September 2026

Frequently Asked Questions

What happens to my shares in a stock split?
In a 2-for-1 split, your shares double and the price per share is halved. Your total investment value stays the same. For example, 100 shares at $200 become 200 shares at $100. Stock splits do not create or destroy value.
Is a stock split good or bad for investors?
A stock split is neutral in terms of value. However, splits can be positive signals because companies usually split when the stock price has risen significantly. Lower prices after a split may attract more retail investors, potentially increasing demand.
How does a reverse stock split work?
A reverse split reduces the number of shares and increases the price proportionally. In a 1-for-10 reverse split, 100 shares at $1 become 10 shares at $10. Reverse splits are often used to meet minimum exchange listing requirements and can signal financial trouble.

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