Stock split basics: share count and price adjust proportionally — total value unchanged. Covers forward vs reverse splits, cost basis, and why companies split.
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.
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.
New Shares = Old Shares × (New : Old ratio) | New Price = Old Price ÷ (New : Old ratio)
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.
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Result
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.
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.
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.
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.