Stock Split Calculator
Calculate how a stock split or reverse split affects your share price and number of shares. Enter your current holdings and split ratio to see post-split results. Total investment value stays the same. Splits only change the number of shares and price per share.
Updated
Educational purposes only.
This calculator provides estimates for educational purposes. Actual post-split values may vary due to rounding of fractional shares. This is not financial advice.
Educational purposes only. These calculators illustrate concepts and do not constitute investment advice. Read our disclaimer
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<a href="https://www.stockcram.com/tools/calculators/stock-split-calculator" target="_blank" rel="noopener">Stock Split Calculator</a>
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</p>What is Stock Split?
A stock split increases the share count and reduces the price per share proportionally, leaving the total value of a holding unchanged. A 4-for-1 split turns 100 shares at $200 into 400 shares at $50: the same $20,000, divided into more pieces.
The formula
New shares = old shares × (numerator ÷ denominator); New price = old price × (denominator ÷ numerator)- numerator ÷ denominator = the split ratio, e.g. 4 ÷ 1 for a 4-for-1
- A reverse split simply inverts the ratio, e.g. 1-for-10
In a 3-for-2 split, 100 shares at $60 become 100 × 1.5 = 150 shares at $60 ÷ 1.5 = $40. Total value stays at $6,000. In a 1-for-10 reverse split, 500 shares at $2 become 50 shares at $20: again $1,000 either side.
What actually changes
A split changes the units, not the underlying claim. Ownership percentage, total position value and the company's market capitalization are all unaffected, because every holder is adjusted by the same ratio at the same moment.
Per-share figures do move, and mechanically so. Earnings per share, dividend per share and the share price all divide by the ratio, while the price-to-earnings ratio does not change: both its numerator and denominator move together.
| Measure | Before | After |
|---|---|---|
| Shares held | 100 | 400 |
| Price per share | $200 | $50 |
| Position value | $20,000 | $20,000 |
| EPS (illustrative) | $8.00 | $2.00 |
| P/E ratio | 25 | 25 |
| Dividend per share | $1.00 | $0.25 |
Reverse splits work the same way in reverse
A reverse split reduces the share count and raises the price by the same ratio. The arithmetic is identical and the position value is likewise unchanged.
The context usually differs. Reverse splits are often associated with raising a share price toward an exchange's minimum listing requirement, since major US exchanges generally require a minimum bid price of $1.00. Forward splits typically follow a rise in price instead.
Some large recent splits
Splits are periodic corporate actions rather than rare events, and several well-known companies have carried them out in recent years.
| Company | Ratio | Effective |
|---|---|---|
| Apple | 4-for-1 | August 2020 |
| Tesla | 5-for-1 | August 2020 |
| Nvidia | 4-for-1 | July 2021 |
| Amazon | 20-for-1 | June 2022 |
| Alphabet | 20-for-1 | July 2022 |
| Tesla | 3-for-1 | August 2022 |
| Nvidia | 10-for-1 | June 2024 |
Dates are when each stock began trading on a split-adjusted basis, per the companies' SEC filings and announcements. Historical corporate actions listed for reference; past performance does not indicate future results.
Cost basis and fractional shares
Cost basis is adjusted by the same ratio, so the total basis is unchanged and no taxable event occurs. 100 shares bought at $200, a $20,000 basis, become 400 shares with a $50 basis each.
Ratios that do not divide evenly can leave a fractional share. Depending on the company and the broker, the fraction may be held as a partial share or paid out in cash, and a cash payment can be a taxable event even though the split itself is not.
What this calculator does not account for
- The calculation is the mechanical adjustment only. It says nothing about how a share price moves afterwards.
- Fractional share handling varies by broker and is not modeled.
- Any cash paid in lieu of a fraction is excluded, though it may be taxable.
- Options contracts are also adjusted at a split, on terms set by the OCC, which this calculator does not cover.
A split rescales an existing basis; the stock average calculator blends the basis across separate purchases. Stock Average Calculator
How It Works
Enter your current share price
The price per share before the split takes effect.
Enter your number of shares
How many shares you currently hold.
Set the split ratio
Choose from common presets (2:1, 4:1, etc.) or enter a custom ratio. Use ratios like 1:2 for reverse splits.
See your post-split holdings
View the new share price, new share count, and verify that total value remains unchanged.
Frequently Asked Questions
A stock split is when a company divides its existing shares into multiple new shares. For example, in a 4-for-1 split, each share becomes 4 shares at one-quarter the original price. The total value of your holdings stays exactly the same — only the number of shares and price per share change.
Companies typically split their stock to make shares more accessible to individual investors by lowering the per-share price. A stock trading at $1,000 may seem expensive, but after a 10-for-1 split it trades at $100. Splits can also increase liquidity and trading volume. Splits do not change the company's market capitalization or fundamental value.
No. A stock split does not change the total value of your investment. If you owned 10 shares at $200 ($2,000 total) and the company does a 2-for-1 split, you now own 20 shares at $100 each, still $2,000 total. The split is purely cosmetic in terms of value.
A reverse stock split consolidates multiple shares into fewer shares at a higher price. In a 1-for-2 reverse split, every 2 shares become 1 share at double the price. Companies sometimes use reverse splits to meet stock exchange minimum price requirements or to reduce the number of outstanding shares. Like forward splits, reverse splits do not change total investment value.
Apple has split five times: 4-for-1 in 2020, 7-for-1 in 2014, and three 2-for-1 splits earlier. Tesla did a 5-for-1 split in 2020 and a 3-for-1 split in 2022. Amazon did a 20-for-1 split in 2022. Alphabet (Google) also did a 20-for-1 split in 2022. These splits made shares more affordable for individual investors while not changing the companies' total market value.