Bonus & Stock Split Adjusted Price Calculator
Find your new adjusted share price and total shares after a bonus issue or stock split on NSE or BSE.
Worked example: original price ₹1000, shares held 100, corporate action Bonus 1:1. Change any input to recalculate.
Portfolio value is unchanged by a bonus or split — only the price per share and share count change. For tax purposes, bonus shares have a cost of acquisition of ₹0. Consult a CA for actual tax advice.
What is a Bonus Issue and Stock Split?
A bonus issue (bonus shares) is when a company allots additional free shares to existing shareholders in proportion to their holdings. A stock split divides existing shares into multiple shares at a proportionally lower price. Both actions do not change the total market value of your holding — only the price per share and number of shares change.
Adjusted Price Formulas
Worked examples for every common ratio
The ratio is the part people get wrong, because a bonus is quoted as shares received per share held while a split is quoted as the number of shares each one becomes. A 1:1 bonus and a 2:1 split produce the same adjusted price by different arithmetic. Each row below starts from 100 shares bought at ₹1,000, a holding worth ₹1,00,000.
| Corporate action | Factor | Shares after | Adjusted price | Value after |
|---|---|---|---|---|
| Bonus 1:1 — one free share per share held | 2.0x | 200 | ₹500.00 | ₹1,00,000 |
| Bonus 2:1 — two free per one held | 3.0x | 300 | ₹333.33 | ₹1,00,000 |
| Bonus 3:1 — three free per one held | 4.0x | 400 | ₹250.00 | ₹1,00,000 |
| Bonus 3:2 — three free per two held | 2.5x | 250 | ₹400.00 | ₹1,00,000 |
| Bonus 1:2 — one free per two held | 1.5x | 150 | ₹666.67 | ₹1,00,000 |
| Split 2:1 — each share becomes two | 2.0x | 200 | ₹500.00 | ₹1,00,000 |
| Split 5:1 — each share becomes five | 5.0x | 500 | ₹200.00 | ₹1,00,000 |
| Split 10:1 — each share becomes ten | 10.0x | 1,000 | ₹100.00 | ₹1,00,000 |
Value after is identical in every row. That is the whole point of the adjustment: the corporate action redistributes the same money across more shares. Anything you read about a bonus "creating" wealth is describing what happened to the price afterwards, not the bonus itself.
When the ratio does not divide evenly
A 3:2 bonus on an odd holding is where the arithmetic stops being tidy. Hold 101 shares and a 3:2 bonus entitles you to 151.5 — but exchanges do not allot half a share. The whole 151 are credited to your demat account and the registrar sells the accumulated fractional entitlements in the market, distributing the proceeds in cash. The payment is small, it arrives separately from the shares, and it often lands weeks later, which is why it surprises people who are reconciling their holdings.
The calculator above reports the fractional entitlement separately for exactly this reason, rather than rounding it away and leaving your share count looking wrong.
Frequently Asked Questions
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Not immediately. A 1:1 bonus doubles your shares but halves the price, so total market value remains the same. However, if the company grows post-bonus and the price recovers, you hold more shares at that higher price, increasing total wealth over time.
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For LTCG/STCG calculation, your cost of acquisition for bonus shares is considered ₹0 as per Indian tax law. Only your original shares retain their purchase cost. This matters significantly when calculating capital gains on selling post-bonus shares.
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NSE and BSE publish corporate action announcements on their websites. The ex-date is when shares trade ex-bonus or ex-split. If you buy on or after the ex-date, you do not receive the bonus or split benefit.