Stock Split Calculator
See how many shares you'll hold and what the new price per share will be after a stock split.
See how many shares you'll hold and what the new price per share will be after a stock split.
How Stock Split Calculator Works
A stock split multiplies your share count by the split ratio and divides the price by the same ratio, so the total dollar value of your holding stays exactly the same — a split doesn't create or destroy any value, it just changes how many pieces that value is divided into.
See It In Action
Who Uses Stock Split Calculator and Why
- Working out the new share count and price per share after a company announces a stock split, like 2-for-1 or 3-for-1.
- Checking a reverse stock split's effect on share count and price, like a 1-for-10 consolidation.
- Confirming that total holding value stays unchanged immediately before and after a split, to avoid confusion when a share price suddenly drops.
- Updating personal investment records after a split to reflect the correct new share count and cost basis per share.
Mistakes to Avoid
- Panicking or celebrating a price drop or jump caused purely by a split — the total value of a holding is identical immediately before and after a split, so a lower per-share price after a split doesn't mean the investment lost value, and a higher price after a reverse split doesn't mean it gained value.
- Entering a reverse split ratio backwards — for a 1-for-10 reverse split, the 'from' and 'to' values need to reflect that share count decreases and price increases, the opposite direction of a regular forward split.
- Forgetting to update per-share cost basis records after a split — while total holding value is unchanged, the average cost per share needs to be recalculated using the new share count for accurate future tax reporting.
Tips for Best Results
- Use this calculator right after a split announcement to immediately see your new share count and adjusted price, so your own records stay accurate ahead of your brokerage statement updating.
- Remember a reverse split (like 1-for-10) uses the exact same formula in the opposite direction as a regular split — same math, just fewer resulting shares at a proportionally higher price.
Fixing Common Problems
My share price dropped a lot and I'm not sure if I lost money. — Check whether a stock split occurred — a split multiplies your share count and divides the price by the same ratio, so the total dollar value of your holding stays exactly the same even though the per-share price looks much lower.
Terms Explained
Stock split: A change in the number of outstanding shares by a fixed ratio, which proportionally adjusts the price per share so total value is unchanged.
Reverse split: A split that reduces share count and proportionally increases price per share, working with the same ratio math in the opposite direction.