Stock Split Calculator
Calculate your new share count and price per share after a stock split. Your total investment value stays the same — everything runs privately in your browser.
How Stock Splits Work
A stock split increases the number of shares you own while proportionally reducing the price per share. Your total investment value remains unchanged. For example, in a 2-for-1 split, you receive two shares for every one share you hold, but each share is worth half the pre-split price. Companies use stock splits to make shares more affordable and increase liquidity.
Stock splits are expressed as a ratio such as 2:1, 3:1, or even fractional like 3:2. The first number indicates how many shares you receive for each share you currently hold. A reverse split works the opposite way — a 1:2 reverse split halves your share count but doubles the price per share.
Formulas
New Shares = Current Shares × (Split Numerator / Split Denominator)
New Price = Current Price × (Split Denominator / Split Numerator)
Total Value = New Shares × New Price (unchanged)
Forward Splits vs Reverse Splits
A forward split (e.g. 2:1, 3:1, 4:1) increases share count and decreases price. Companies like Apple, Tesla, and Amazon have used forward splits to make their stock more accessible to retail investors. A reverse split (e.g. 1:5, 1:10) decreases share count and increases price. Companies use reverse splits to meet minimum price requirements for stock exchange listings or to improve perception among institutional investors.
Both forward and reverse splits are non-taxable events in most jurisdictions. Your cost basis per share adjusts proportionally, and the total value of your position does not change at the moment of the split. However, splits can affect market sentiment and trading volume, which may indirectly influence price over time.
Common Stock Split Ratios
- 2-for-1: Most common split. Share count doubles, price halves.
- 3-for-1: Used by companies with very high share prices.
- 4-for-1: Apple used this ratio in August 2020.
- 10-for-1: Nvidia used this in June 2024.
- 3-for-2: A fractional split — 100 shares become 150.
- 1-for-10: Reverse split — 1000 shares become 100.
Why Companies Split Their Stock
Companies split their stock primarily to improve share price accessibility. When a stock price climbs very high, smaller investors may be unable to purchase even a single share. A split brings the price back to a more approachable range without changing the company's market capitalization. Splits also tend to increase trading volume and liquidity, as more shares are available at lower price points. Studies show that stocks often experience positive momentum after a split announcement, though the split itself does not change the fundamental value of the company.
Frequently Asked Questions
Does a stock split change the value of my investment?
No. A stock split changes the number of shares you own and the price per share, but the total value of your investment remains exactly the same immediately after the split. It is purely a cosmetic change to the share structure.
What is a reverse stock split?
A reverse stock split reduces the number of shares outstanding while increasing the price per share proportionally. For example, a 1:10 reverse split turns 1000 shares at $1 each into 100 shares at $10 each. Companies use reverse splits to meet exchange listing requirements or improve institutional perception.
How does a stock split affect my cost basis?
Your total cost basis stays the same, but the cost basis per share adjusts proportionally. In a 2:1 split, if your original cost basis was $100 per share, the new cost basis becomes $50 per share. This is important for calculating capital gains when you sell.
Are stock splits taxable events?
No, stock splits are generally not taxable events in most countries including the US and UK. You do not owe any taxes at the time of a split. Taxes only apply when you eventually sell your shares and realize a capital gain or loss.
Can fractional shares result from a stock split?
Yes. If you hold an odd number of shares in a split like 3:2, you may end up with fractional shares. Some brokers handle this by giving you cash in lieu of fractional shares, while others support fractional share ownership. Check with your broker for their specific policy.