Swap ratio explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
When one company takes over another by issuing its own shares, the central question is how many new shares each holder of the smaller company receives. That number is the swap ratio. A ratio that is too generous dilutes the buying company's owners; one that is too tight leaves the smaller company's owners with too little. The arithmetic gives the range both sides can accept, and the owners then bargain within it.
Swap ratio = shares of the acquiring company given for each share of the target. It can be based on earnings per share (EPS), on the value per share (market price, or an agreed value for an unlisted company) or on book value per share: ratio = target's figure / acquirer's figure. Compute the shares to be issued, the combined EPS and the effect on each group of owners. A workable ratio sits between the lowest the target's owners will accept and the highest the acquirer's owners can bear without dilution.
What the swap ratio is and where gains come from
A merger can add value when the combined business earns more than the two separately: through savings in costs, wider markets or better use of assets. This extra gain is synergy. Without synergy, a merger by share exchange only redistributes ownership of the same profit. With synergy, the question is how the gain is shared, and the ratio decides that.
The law of mergers is separate from this arithmetic. The scheme, the valuation by a registered valuer and the approvals are set out in our guides on section 232 (merger), section 230 compromise and arrangement and merger and demerger under the Companies Act and the income tax law. This article covers the numbers only. For modelling a combination, a financial model helps.
The bases for the ratio
| Basis | Ratio in words | Symbols |
|---|---|---|
| EPS | Target's EPS over acquirer's EPS | EPS_T / EPS_A |
| Value per share | Target's value per share over acquirer's | V_T / V_A |
| Book value per share | Target's book value over acquirer's | B_T / B_A |
Shares to be issued = target's shares x swap ratio. Combined EPS = combined profit after tax / (acquirer's shares + shares issued). An owner of the target compares the EPS-equivalent of the shares received (ratio x combined EPS) with the old EPS, and also compares the value of the new shares with the value of the old ones.
Worked example: Alpha Foods and Beta Bakers
Two invented unlisted companies. Because neither has a quoted price, an agreed value per share, which is an assumption, replaces market price.
| Alpha Foods (acquirer) | Beta Bakers (target) | |
|---|---|---|
| Profit after tax (₹ lakh) | 60 | 20 |
| Shares (lakh) | 10 | 5 |
| EPS (₹) | 6.00 | 4.00 |
| Agreed value per share (₹) | 90 | 48 |
| Book value per share (₹) | 50 | 40 |
Ratios. On EPS: 4 / 6 = 0.6667 (2 Alpha shares for 3 Beta shares). On agreed value: 48 / 90 = 0.5333 (8 Alpha shares for 15 Beta shares). On book value: 40 / 50 = 0.8000 (4 Alpha shares for 5 Beta shares).
Results without synergy (combined profit 60 + 20 = 80 lakh):
| Basis | Ratio | New shares issued (lakh) | Total shares (lakh) | Combined EPS (₹) | EPS-equivalent for one Beta share (₹) | Value of Alpha shares received per Beta share (₹) |
|---|---|---|---|---|---|---|
| EPS | 0.6667 | 5 x 0.6667 = 3.3333 | 13.3333 | 80 / 13.3333 = 6.00 | 0.6667 x 6.00 = 4.00 | 0.6667 x 90 = 60.00 |
| Agreed value | 0.5333 | 5 x 0.5333 = 2.6667 | 12.6667 | 80 / 12.6667 = 6.32 | 0.5333 x 6.3158 = 3.37 | 0.5333 x 90 = 48.00 |
| Book value | 0.8000 | 5 x 0.8 = 4.0000 | 14.0000 | 80 / 14 = 5.71 | 0.8 x 5.7143 = 4.57 | 0.8 x 90 = 72.00 |
Figures rounded to two decimals; the combined EPS used in the next column is unrounded.
Reading the table.
- On the EPS basis neither side's EPS changes: Alpha holders still have ₹6.00 and a Beta holder's share is worth ₹4.00 of earnings. Beta's owners, however, receive Alpha shares worth ₹60 against their old ₹48, which is generous to Beta.
- On the value basis Beta's owners receive exactly the value they hold (₹48) but their EPS-equivalent falls from ₹4.00 to ₹3.37. Alpha's EPS rises from ₹6.00 to ₹6.32, since Alpha's shares are valued at a higher multiple of earnings.
- On book value Beta's owners receive ₹72 of value per share and Alpha's EPS falls to ₹5.71.
The range. Alpha's owners are not diluted as long as combined EPS is at least ₹6.00, which requires 10 + 5r no more than 80 / 6 = 13.3333, that is r no more than 0.6667. Beta's owners will not accept less than the value they hold, which requires r of at least 0.5333. The workable range is from 0.5333 to 0.6667.
With synergy. Suppose the combination adds ₹10 lakh of profit, making 90 lakh. At the value ratio of 0.5333, combined EPS = 90 / 12.6667 = ₹7.11 (7.1053); a Beta holder's EPS-equivalent = 0.5333 x 7.1053 = ₹3.79, still below ₹4.00, while Alpha's holders gain more. At a ratio of 0.60 (3 Alpha shares for 5 Beta shares), total shares are 10 + 3 = 13 lakh, EPS = 90 / 13 = ₹6.92, and the Beta equivalent is 0.60 x 6.9231 = ₹4.15, so both sides are better off than before. The owners therefore bargain at about 0.60, giving 3 Alpha shares for every 5 Beta shares.
Choosing the basis
EPS is easy but ignores growth and risk. Value reflects what each side believes its business is worth; for unlisted firms it comes from a valuation and the assumptions behind it must be stated. Book value reflects assets and suits asset-heavy firms, but ignores earning power. Many deals blend the bases with weights both sides accept. The cost of capital of the combined business is explained in cost of capital.
Common mistakes
- Using market price for an unlisted firm without a valuation.
- Comparing EPS before and after but ignoring the value each side gives up.
- Counting synergy that is only hoped for as certain profit.
- Forgetting fractional shares and how they will be settled.
- Treating the ratio as final before the approvals and valuer's report.
- Ignoring the effect on control: the share of the combined company each side holds. Here Beta's owners would hold 3.0 of 13 lakh shares, about 23 per cent, at a ratio of 0.60.
Need help with merger numbers?
If you are weighing a merger or a share exchange, our financial modeling service builds the before and after statements, the swap ratio on each basis and the effect on each group of owners. You can see the range of acceptable ratios before the negotiation begins.
Key takeaways
- Swap ratio = target's figure over acquirer's figure, on EPS, value or book value.
- Shares issued = target's shares x ratio.
- Compare each side's EPS and value before and after.
- Find the range between what the target's owners need and what the acquirer's owners can bear.
- Law and approvals are separate: use the linked guides.
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Disclaimer: The methods described are standard cost accounting and financial management techniques. The worked example uses an invented business and invented figures, including any tax, interest or exchange rate, which are assumptions for illustration and not current rates. Where the article refers to a legal requirement, the linked guide and the official text should be checked. This article is general information, not legal advice; check the official text before acting.