Stock Split Calculator
Instantly recalculates your share count and adjusted price after a forward or reverse stock split. Use it when a company announces a split and you want to know the exact impact on your holdings.
Last updated: September 2026
Formula below · 2 sources (investor.gov, Wikipedia) · Updated Sep 2026
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About this calculator
A stock split changes the number of shares outstanding without altering the company's total market capitalisation. In a forward split (e.g., 2-for-1), each existing share becomes multiple shares and the price is reduced proportionally. In a reverse split (e.g., 1-for-5), multiple shares are consolidated into one and the price rises proportionally. Enter the ratio as it is announced — 2-for-1 is New = 2, Old = 1; a 1-for-10 reverse split is New = 1, Old = 10 — and pick the split type. For a forward split: New Shares = Current Shares × (larger number / smaller number). For a reverse split: New Shares = Current Shares × (smaller number / larger number), so a 1-for-10 reverse split gives the same answer whether you type 1 and 10 or 10 and 1. The price adjusts inversely by the same factor, keeping total position value constant. Understanding both directions is essential for tracking cost basis and evaluating portfolio impact.
How to use
Imagine you hold 200 shares of a stock priced at $150, and the company announces a 3-for-1 forward split. splitRatioNew = 3, splitRatioOld = 1. New Shares = 200 × (3 / 1) = 600 shares. New Price = $150 × (1 / 3) = $50 per share. Your total position value stays the same: 600 × $50 = $30,000 (equal to 200 × $150 = $30,000). For a 1-for-3 reverse split on the same 200 shares, enter New = 1, Old = 3 and choose Reverse Split: New Shares = 200 × (1 / 3) = 66.67 shares, and New Price = $150 × 3 = $450, so the position is still worth 66.67 × $450 = $30,000. Most brokers issue 66 whole shares and pay cash in lieu of the 0.67 fractional share.
Frequently asked questions
Why do companies do a forward stock split instead of keeping the share price high?
Companies typically split shares to improve affordability and liquidity. A lower per-share price makes the stock accessible to a wider range of retail investors who cannot purchase fractional shares. Higher trading volume from broader participation can reduce bid-ask spreads and improve price discovery. Companies like Apple and Tesla have used forward splits when their share prices reached levels that may have felt psychologically expensive to smaller investors. The split itself creates no fundamental value change.
What happens to my stock options or warrants when a stock split occurs?
Stock options and warrants are typically adjusted automatically by the exchange or brokerage to reflect the split. In a 2-for-1 forward split, each option contract (normally covering 100 shares) would cover 200 shares and the strike price would be halved. This ensures the total economic value of the option position remains unchanged. You should confirm the adjustment terms with your broker, as specific mechanics can vary for non-standard splits or certain derivative instruments.
How does a reverse stock split affect a company's share price and investor perception?
A reverse split raises the nominal share price by consolidating shares, which companies often do to meet minimum price requirements of exchanges like NYSE or NASDAQ (typically $1). While the total market cap is unchanged immediately after the split, reverse splits are often viewed negatively by investors as a signal of financial distress. Academic studies show stocks tend to underperform after reverse splits, partly because the action draws attention to prior price weakness. However, if accompanied by genuine business improvement, a reverse split can be a neutral or positive restructuring tool.