Stock Split Calculator

Calculate how a stock split affects your shares and their price. Works for both forward splits (like 2-for-1) and reverse splits (like 1-for-10). See your new share count and adjusted price per share.

for

Example: "5 for 1" means you get 5 shares for every 1 share you own

Forward Split
New Share Price
$100.00
Before Split: Shares 100
After Split: Shares 500
Before Split: Price $500.00
After Split: Price $100.00
Total Value (unchanged) $50,000.00
In a 5-for-1 split, each share becomes 5 shares, and the price is divided by 5. Your total value stays the same.
Visual Representation of Stock Split
500
shares @ $100.00

Total Portfolio Value: $50,000.00

Metric Before Split After Split Change
Number of Shares100500+400 (+400%)
Price per Share$500.00$100.00-$400.00 (-80%)
Total Value$50,000.00$50,000.00$0.00 (0%)
Cost Basis per Share$500.00$100.00-$400.00 (-80%)
Share Count & Price Before vs After Split

What is a Stock Split?

A stock split is a corporate action in which a company divides its existing shares into multiple shares. While the number of shares outstanding increases, the total dollar value of the shares remains the same because the split doesn't add real value.

Think of it like exchanging a $100 bill for five $20 bills. You have more individual units, but the total value remains $100.

Key Point: A stock split does NOT change the total value of your investment. If you owned $10,000 worth of stock before the split, you still own $10,000 after the split. Only the number of shares and price per share change.

How Does a Stock Split Work?

The mechanics of a stock split are straightforward:

Stock Split Formulas:

Forward Split (e.g., 5-for-1):
New Shares = Old Shares × Split Ratio
New Price = Old Price ÷ Split Ratio

Reverse Split (e.g., 1-for-10):
New Shares = Old Shares ÷ Reverse Ratio
New Price = Old Price × Reverse Ratio

Example: 5-for-1 Split

If you own 100 shares at $500 per share:

Forward (Regular) Stock Splits

A forward split increases the number of shares while reducing the price per share proportionally. Common split ratios include:

Split Ratio Effect on Shares Effect on Price Example ($500 stock)
2-for-1 ×2 ÷2 → $250
3-for-1 ×3 ÷3 → $166.67
4-for-1 ×4 ÷4 → $125
5-for-1 ×5 ÷5 → $100
10-for-1 ×10 ÷10 → $50
20-for-1 ×20 ÷20 → $25

Reverse Stock Splits

A reverse split reduces the number of shares while increasing the price per share. This is the opposite of a forward split.

Why Companies Do Reverse Splits

Warning: Reverse splits are often viewed negatively as they're typically done by struggling companies trying to avoid delisting. However, this isn't always the case—some healthy companies do reverse splits for strategic reasons.

Why Do Companies Split Their Stock?

Companies split their stock for several reasons:

1. Increase Accessibility

A lower share price makes the stock more affordable for retail investors who may not want to invest hundreds of dollars per share.

2. Improve Liquidity

More shares at a lower price often leads to higher trading volume and better liquidity.

3. Psychological Appeal

Some investors prefer buying "whole shares" and a $100 stock may be more appealing than a $1,000 stock, even if the value is the same relative to their investment.

4. Index Inclusion

Some price-weighted indices (like the Dow Jones) are affected by stock prices, so splits can impact index weighting.

How Splits Affect Dividends

Stock splits also affect dividend payments proportionally:

Example

Before a 2-for-1 split: 100 shares, $2 dividend per share = $200 total

After split: 200 shares, $1 dividend per share = $200 total

Famous Stock Splits

Many well-known companies have executed significant stock splits:

Apple (AAPL)
4-for-1
August 2020
Tesla (TSLA)
5-for-1
August 2020
Amazon (AMZN)
20-for-1
June 2022
Alphabet (GOOGL)
20-for-1
July 2022
NVIDIA (NVDA)
10-for-1
June 2024
Walmart (WMT)
3-for-1
February 2024

Frequently Asked Questions

Do I need to do anything when my stock splits?

No, stock splits happen automatically. Your brokerage will update your share count and adjust the price. You don't need to take any action.

Do stock splits create a taxable event?

No, stock splits are not taxable events. However, your cost basis per share will be adjusted proportionally. When you eventually sell, you'll calculate gains using the adjusted cost basis.

Are stock splits good or bad?

Stock splits are generally considered neutral events since they don't change the company's value. However, they can signal that a company's stock has been performing well. Some studies suggest stocks may perform better after splits due to increased accessibility and trading activity.

What happens to fractional shares in a reverse split?

If a reverse split results in fractional shares, companies typically either pay cash for the fractional portion or round up/down to the nearest whole share, depending on company policy.

How do splits affect options contracts?

Options contracts are adjusted after a split. The number of contracts, strike prices, and contract sizes are all adjusted proportionally to reflect the split. Your overall position value remains unchanged.

Can I predict when a company will split its stock?

While you can't predict exactly when a split will occur, companies often split when their stock price becomes relatively high. Tech companies with triple or quadruple-digit stock prices are common candidates. Companies announce splits in advance, typically giving shareholders several weeks' notice.