Enter your shares held, your average buy price and the split ratio. This stock split calculator shows your new share count and new average price, which is also your tax cost, unlike a bonus issue.
Stock Split Calculator
For a face value split, such as 1:10. Ratio is old shares becoming new shares.
A split is tax-neutral: your cost carries forward, apportioned across more shares, and your holding period is unchanged.
Your holding in detail
| Item | Value |
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Illustrative calculation. Does not include brokerage or charges, and is not tax advice.
A company announces a 1:10 split, and 100 shares at ₹1,000 become 1,000 shares at ₹100. Nothing about your investment has actually changed, only how finely it is sliced. A stock split calculator shows the new count and the new price, and the tax rule that makes a split completely different from a bonus issue.
How do you use this stock split calculator in 3 steps?
- Enter the shares you hold and your average buy price.
- Enter the split ratio, as old shares becoming new shares, such as 1 becoming 10.
- Add the market price before the split if you want the theoretical post-split price, then read the new average and the tax notes.
Stock Charcha’s stock split calculator shows one average price that does double duty, for your own tracking and for your tax cost, which is the key difference from a bonus issue.
How does the stock split calculator work out the new share count?
A split changes the face value of the share, so the company’s reserves and your investment are untouched. Your shares are simply subdivided into more, smaller pieces.
Total shares after split = Shares held × (New ÷ Old), rounded down
New average price = Total amount invested ÷ Total shares after the split
Unlike a bonus issue, this new average price is not just a tracking number. It is also the figure the tax rules recognise as your cost per share, because a split does not create any new asset for free. Stock Charcha keeps both calculators on the same page structure so the contrast is easy to see.
What does a worked example look like?
Take 100 shares bought at ₹1,000, with a 1:10 split. These figures are illustrative.
| Item | Value |
|---|---|
| Total shares after the split | 1,000 |
| Total amount invested | ₹1,00,000 (unchanged) |
| New average price | ₹100.00 |
| Theoretical post-split price (market was ₹1,000) | ₹100.00 |
Your portfolio value does not change on the day of the split, only the number of shares it is held in and the price tag on each one.
How does the split ratio change the outcome?
Here is the same 100 shares at ₹1,000 under different common ratios.
| Ratio | Total shares | New average price |
|---|---|---|
| 1:2 | 200 | ₹500.00 |
| 1:5 | 500 | ₹200.00 |
| 1:10 | 1000 | ₹100.00 |
A bigger split makes the price per share smaller and more accessible, which is often the company’s stated reason for doing one, but your total holding value and your total cost do not move. A smaller ratio, such as 1:2, makes a gentler change, while a 1:10 split can turn a high-priced stock into one that looks far more affordable on paper.
Why is a split tax-neutral, unlike a bonus issue?
This is the sharpest contrast between the two. In a bonus issue, new shares are created from the company’s reserves, and the tax rules treat their cost as Nil. In a split, no new shares are created at all, the existing ones are simply subdivided, so your original cost is apportioned across them rather than wiped to zero.
| Point | Stock Split | Bonus Issue |
|---|---|---|
| New shares created | No, existing ones subdivided | Yes, from reserves |
| Tax cost of acquisition | Original cost, apportioned | Nil |
| Holding period | Unchanged, from original purchase | Starts fresh from allotment |
If you later sell split shares, there is no separate lot to track and no Nil-cost shock. Compare this with our bonus share calculator to see the Nil-cost case side by side.
What does this stock split calculator leave out?
It does not include brokerage or charges on any later sale, which our brokerage calculator covers. It also assumes a simple forward split and does not cover a reverse split, where shares are consolidated rather than subdivided. For tax on an eventual sale, use the share capital gains tax calculator.
This is an estimate, not tax advice. The position for stock splits is not spelled out in the Income Tax Act as explicitly as it is for bonus shares, though tax practitioners consistently apply the apportioned-cost, unchanged-holding-period treatment described here. Confirm with a chartered accountant for a large holding.
Where should you go after using the stock split calculator?
For the Nil-cost case, see the bonus share calculator. To track your overall cost across several purchases, use the stock average calculator, and for tax on a sale, the share capital gains tax calculator.
The Investing section of the Charcha Knowledge Hub has more. Run the Stock Charcha stock split calculator the next time a company you hold announces one.
Related calculators
- Bonus share calculator
- Stock average calculator
- Share capital gains tax calculator
- Brokerage calculator
Last updated: 3 October 2026. Tax position checked on 3 October 2026, based on consistent practitioner treatment under Section 55(2)(b) of the Income Tax Act. Review if guidance changes.
Founder of Stock Charcha. Stock market enthusiast, actively investing since November 2022. About the author
Educational content only. This page is not personalised financial or tax advice, and nothing here is a recommendation to buy or sell any stock. Please do your own research or speak to a SEBI-registered adviser or a chartered accountant, and read our disclaimer.
Frequently asked questions
Is a stock split taxed when I receive the new shares?
No. There is no tax at the time of a split, since it only subdivides your existing shares and creates no new asset or income. Tax applies only when you eventually sell, based on your original cost and holding period.
What is the cost of acquisition for split shares?
Your original purchase cost is apportioned across the larger number of shares after the split. The total cost in rupees stays the same, but the cost per share falls, and this apportioned figure is what tax rules recognise, not Nil.
Does the holding period reset after a stock split?
No. The holding period carries over unchanged from your original purchase date, because a split does not create a new asset, it only subdivides the one you already held. This is the opposite of a bonus issue.
How is a stock split different from a bonus issue for tax purposes?
A split apportions your existing cost across more shares with the holding period unchanged. A bonus issue creates new shares with a Nil tax cost and a holding period that starts fresh from the allotment date, which can mean a bigger tax bill if sold soon after.
Can I use the stock split calculator for a reverse split?
No. This calculator covers a standard split that increases your share count. A reverse split consolidates shares into fewer, more expensive ones, and the mechanics differ, so check with your broker or a different tool for that case.