Stock Split Calculator
Calculate shares and price per share after any forward or reverse stock split. Enter your holdings and split ratio to see your adjusted position instantly.
Added Jun 16, 2026
Input
For a 2-for-1 split, enter 2. For a 3-for-1 split, enter 3.
For a 2-for-1 split, enter 1. For a 1-for-3 reverse split, enter 3.
Result
Enter a value for shares owned to see your result.
How it works
Calculates your new share count and adjusted share price after a forward or reverse stock split. Total portfolio value is unchanged — splits only adjust the number of shares and price per share proportionally.
Formula
New Shares = Old Shares × (New : Old ratio) | New Price = Old Price ÷ (New : Old ratio)
- Split ratio
- e.g. 2:1 means 2 new shares per 1 old share (forward split)
- New Shares
- Old shares × (numerator ÷ denominator)
- New Price
- Old price × (denominator ÷ numerator)
- Total value
- Unchanged — splits do not affect portfolio value
Step by step
- 01Enter how many shares you currently own and the current price per share.
- 02Enter the split ratio: for a 2-for-1 split, numerator = 2, denominator = 1.
- 03For a reverse split (e.g. 1-for-3), numerator = 1, denominator = 3.
- 04New shares = old shares × (numerator ÷ denominator).
- 05New price = old price × (denominator ÷ numerator) — total value stays the same.
Examples
2-for-1 split: 100 shares at $150
A 2-for-1 split doubles your share count from 100 to 200 and halves the price from $150 to $75. Total value remains $15,000.
Inputs
- Shares owned:
- 100
- Current share price:
- 150
- Split ratio (new shares):
- 2
- Split ratio (old shares):
- 1
Result
- Shares after split:
- 200
- Price per share after split:
- 75
- Total value before split:
- 15000
- Total value after split:
- 15000
Frequently asked questions
What is a stock split?
A stock split divides existing shares into more shares at a proportionally lower price. For example, a 2-for-1 split turns 100 shares at $150 each into 200 shares at $75 each. Total investment value is unchanged. Companies typically split to make shares more affordable and increase trading volume.
What is a reverse stock split?
A reverse stock split consolidates existing shares into fewer shares at a proportionally higher price. A 1-for-10 reverse split turns 100 shares at $1 into 10 shares at $10. Reverse splits are often used by companies to avoid being delisted from exchanges with minimum price requirements.
Does a stock split affect my investment value?
No. A stock split does not change the total value of your holdings. If you had $15,000 worth of stock before a 2-for-1 split, you still have $15,000 worth after — just in more shares at a lower price per share.
What happens to my cost basis after a stock split?
Your total cost basis is unchanged, but the per-share cost basis adjusts proportionally. If you paid $100/share and the stock splits 2-for-1, your new per-share cost basis is $50. This matters for capital gains tax when you sell.