Advanced Financial Management · Mergers, Acquisitions and Corporate Restructuring

Exchange Ratio and Post-Merger EPS Analysis

Updated 5 October 2026 · Fact-checked

The exchange ratio is the number of acquirer shares given for each target share. Compute it as target value per share ÷ acquirer value per share, using EPS, market price, book value or intrinsic value. Then add the earnings, divide by total shares after issue to get post-merger EPS, and multiply by P/E for price.

Understand Exchange Ratio and Post-Merger EPS Analysis

In a stock-for-stock merger, the acquirer pays target shareholders with its own shares. The exchange ratio says how many acquirer shares one target share gets. A ratio of 0.6 means 6 acquirer shares for every 10 target shares.

Swap ratio and exchange ratio mean the same thing in exam answers. Some books use "swap ratio" for the deal terms and "exchange ratio" for the calculated figure, but the formula is identical. Do not waste time on the difference.

The ratio depends on which value you compare. EPS basis compares earning power. Market price basis compares what the market pays today. Book value basis compares net assets per share. Intrinsic value basis compares your own estimate of worth per share. Each basis gives a different ratio, so read which one the question asks for. If it gives several, use a weighted average of the ratios.

After the swap, the acquirer issues new shares, so its share count rises. Post-merger EPS is combined earnings (plus any synergy) divided by the enlarged share count. If the target is bought at a higher P/E than the acquirer's, or at a ratio above its EPS ratio, acquirer EPS falls. This is EPS dilution. If it rises, it is accretion.

Post-merger market price is usually found as post-merger EPS × post-merger P/E. The P/E is either given or assumed to be the acquirer's old P/E. Then compare the value each group of shareholders holds before and after. That shows who gains from the merger.

Key rules to remember

Exchange ratio (EPS basis): ER = EPS of target ÷ EPS of acquirer; Leaves the acquirer's EPS unchanged at the combined level, apart from synergy.
Exchange ratio (market price basis): ER = MPS of target ÷ MPS of acquirer; Gives target holders the same market value at pre-merger prices. A premium, if stated, is added to the target price first.
Exchange ratio (book value basis): ER = Book value per share of target ÷ Book value per share of acquirer; Book value per share = net worth ÷ number of equity shares.
Exchange ratio (intrinsic value basis): ER = Intrinsic value per share of target ÷ Intrinsic value per share of acquirer; Use the values given, or compute them from the valuation method stated.
Weighted average ratio: ER = Σ (weight × ER on each basis); Use only when the question gives weights or asks for a combined ratio.
New shares issued: New shares = Target shares × ER; Keep fractions until the end, then round only the final answer.
Post-merger EPS: EPS = (Earnings of A + Earnings of B + synergy) ÷ (Shares of A + New shares); Use after-tax earnings available to equity holders.
EPS accretion or dilution: Change = Post-merger EPS − Acquirer's old EPS; Positive means accretion, negative means dilution.
Equivalent EPS of target holder: Equivalent EPS = Post-merger EPS × ER; Compare with the target's old EPS.
Post-merger market price: Price = Post-merger EPS × Post-merger P/E; If no P/E is given, state your assumption, usually the acquirer's old P/E.
Value to target holder per old share: Value = ER × Post-merger price; Compare with the target's old market price for the gain or loss.

How to solve Exchange Ratio and Post-Merger EPS Analysis questions

Use this order for any exchange ratio and post-merger question. Keep a small table of both companies' earnings, shares, EPS, price and P/E first.

1Write a data table: earnings, number of shares, EPS, MPS, P/E and book value for both companies. Fill in any missing EPS = earnings ÷ shares.
2Identify the basis asked: EPS, market price, book value, intrinsic value or a weighted mix. Check for a stated premium or synergy.
3Compute the exchange ratio as target value per share ÷ acquirer value per share. Keep four decimal places.
4Find new shares = target shares × ER. Add them to the acquirer's shares to get the total after the merger.
5Find post-merger EPS = combined earnings (plus synergy) ÷ total shares. Compare with the acquirer's old EPS and state accretion or dilution.
6Find post-merger price = EPS × P/E, using the P/E given or the acquirer's old P/E with the assumption stated.
7Compute each group's value: acquirer holders = old shares × new price; target holders = new shares × new price. Compare with their pre-merger market values.
8Check that the total gain equals combined value after − combined value before, then write the conclusion in one line.

Quickest way: Table-and-reconcile shortcut

When to use it: Use when you have limited time and the question asks for ER, EPS and gain to each side together.

Get EPS and MPS of both companies in one line each.
Compute ER and new shares at once. Use ER × target shares.
Compute post-merger EPS from total earnings ÷ total shares.
Multiply by the P/E to get the price. Value of the whole firm = total shares × price.
Check: total value after − (value of A + value of B before) equals the sum of the two groups' gains. If not, find the slip before writing the answer.

Common mistakes in Exchange Ratio and Post-Merger EPS Analysis

Inverting the ratio, writing acquirer ÷ target.
Students remember "divide one by the other" without checking which company issues shares.
Fix: Target is always on top. The ratio can be above or below 1, depending on the per-share values.
Using old share count of the acquirer for post-merger EPS.
The new shares issued to target holders are forgotten once the ratio is found.
Fix: Always compute new shares = target shares × ER and add them before dividing earnings.
Rounding the ER to two decimals early.
It looks neater, but it changes new shares and every figure after it.
Fix: Carry four decimals or the exact fraction, and round only the final answers.
Applying the target's old P/E to the combined EPS.
Students pick any P/E from the table.
Fix: Use the P/E the question gives for the merged firm. If none is given, assume the acquirer's P/E and write that assumption.
Declaring gain from EPS alone.
Higher EPS looks like a gain, but market price matters for shareholder wealth.
Fix: Compare value held before and after, using the new market price for each group, and make sure the totals reconcile.
Forgetting synergy or a stated premium.
Extra information in the last line of the question gets missed.
Fix: Underline synergy, premium and any change in P/E in the question before starting.

Worked examples

Example 1

A Ltd plans to acquire B Ltd by issuing shares. A Ltd: earnings ₹60,00,000, 10,00,000 shares, market price ₹90. B Ltd: earnings ₹20,00,000, 5,00,000 shares, market price ₹54. The exchange ratio is based on market price. Assume A's P/E stays unchanged after the merger and there is no synergy. Find (a) the ratio and new shares, (b) post-merger EPS and effect on each side, (c) post-merger price and gain to each group.

Show the solution

EPS of A = 60,00,000 ÷ 10,00,000 = ₹6. P/E of A = 90 ÷ 6 = 15. EPS of B = 20,00,000 ÷ 5,00,000 = ₹4. P/E of B = 54 ÷ 4 = 13.5.
ER = 54 ÷ 90 = 0.6. New shares = 5,00,000 × 0.6 = 3,00,000. Total shares = 13,00,000.
Combined earnings = ₹80,00,000. Post-merger EPS = 80,00,000 ÷ 13,00,000 = ₹6.1538, about ₹6.15. This is above ₹6, so A's EPS is accreted.
Equivalent EPS to B holders = 6.1538 × 0.6 = ₹3.69, below their old ₹4. Their EPS is diluted, but see price below.
Post-merger price = 6.1538 × 15 = ₹92.31 (approx).
B holders' value per old share = 0.6 × 92.31 = ₹55.38, against ₹54: gain ₹1.38.
Value before: A = 10,00,000 × 90 = ₹9,00,00,000; B = 5,00,000 × 54 = ₹2,70,00,000; total ₹11,70,00,000.
Value after = 13,00,000 × 92.3077 = ₹12,00,00,000. Total gain = ₹30,00,000.
A holders: 10,00,000 × 92.3077 = ₹9,23,07,692, a gain of about ₹23,07,692. B holders: 3,00,000 × 92.3077 = ₹2,76,92,308, a gain of about ₹6,92,308. Sum = ₹30,00,000.

Answer: ER = 0.6 and 3,00,000 new shares. Post-merger EPS is about ₹6.15 (accretive for A). Post-merger price is about ₹92.31. A holders gain about ₹23.08 lakh and B holders gain about ₹6.92 lakh, a total of ₹30 lakh.

Example 2

X Ltd has 4,00,000 shares, EPS ₹10 and market price ₹150. Y Ltd has 2,00,000 shares, EPS ₹5 and market price ₹60. X will acquire Y by issuing shares. Compare the deal at an exchange ratio based on (a) EPS and (b) market price. Assume X's P/E is retained and there is no synergy.

Show the solution

Earnings: X = 4,00,000 × 10 = ₹40,00,000; Y = 2,00,000 × 5 = ₹10,00,000; combined ₹50,00,000. X's P/E = 150 ÷ 10 = 15. Pre-merger value: X = ₹6,00,00,000; Y = ₹1,20,00,000; total ₹7,20,00,000.
(a) EPS basis: ER = 5 ÷ 10 = 0.5. New shares = 2,00,000 × 0.5 = 1,00,000. Total shares = 5,00,000.
Post-merger EPS = 50,00,000 ÷ 5,00,000 = ₹10, the same as before, so there is no dilution for X. Price = 10 × 15 = ₹150.
Y holders: 0.5 × 150 = ₹75 per old share against ₹60, a gain of ₹15. Total value after = 5,00,000 × 150 = ₹7,50,00,000, a gain of ₹30,00,000. Y holders gain 1,00,000 × 150 − 1,20,00,000 = ₹30,00,000, so X holders gain nothing.
(b) Market price basis: ER = 60 ÷ 150 = 0.4. New shares = 2,00,000 × 0.4 = 80,000. Total shares = 4,80,000.
Post-merger EPS = 50,00,000 ÷ 4,80,000 = ₹10.4167, about ₹10.42, which is accretive for X. Price = 10.4167 × 15 = ₹156.25.
X holders: 4,00,000 × (156.25 − 150) = ₹25,00,000 gain. Y holders: 80,000 × 156.25 = ₹1,25,00,000 against ₹1,20,00,000, a gain of ₹5,00,000. Total gain = ₹30,00,000.
Compare: the EPS basis gives all the gain to Y holders because Y has a lower P/E (12) than X (15). The market basis shares the gain, and X holders get most of it.

Answer: EPS basis: ER 0.5, EPS stays ₹10, price ₹150, and Y holders gain ₹30 lakh. Market basis: ER 0.4, EPS about ₹10.42, price ₹156.25, X holders gain ₹25 lakh and Y holders gain ₹5 lakh. X would prefer the market-price ratio.

Exam tips

Write the data table first. Most marks in these sums come from correct EPS, P/E and share counts, and a table makes errors easy to spot.
State your assumption on post-merger P/E in one line whenever the question does not give it. Examiners give marks for a stated, sensible assumption.
Show the reconciliation of total gain. It proves your numbers are consistent, and in MCQs it lets you check an option quickly.
In a case-scenario MCQ, decide first whether the question wants ER, new shares, EPS or price. Then compute only that, not the whole table.
Finish with a one-line interpretation: accretive or dilutive, and which group gains. Descriptive answers lose marks when they stop at the numbers.

Practice questions from Mergers, Acquisitions and Corporate Restructuring

Exchange Ratio and Post-Merger EPS Analysis in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Exchange Ratio and Post-Merger EPS Analysis: frequently asked questions

How do I calculate the swap ratio in CA Final AFM?

Divide the target's value per share by the acquirer's value per share on the basis the question gives. Common bases are EPS, market price, book value and intrinsic value. The result is the number of acquirer shares given for each target share.

What is the difference between exchange ratio and swap ratio?

In practice there is none. Both are the number of acquirer shares offered per target share, and the formula is the same. Use whichever term the question uses.

Why does EPS fall after a merger?

EPS falls when the acquirer issues so many new shares that earnings per share, spread over the larger count, are lower. This happens when the target is bought at a higher price relative to its earnings than the acquirer's own. It is called EPS dilution.

Which P/E should I use for post-merger market price?

Use the P/E given in the question. If none is given, assume the acquirer's existing P/E and write that assumption. If the question gives a different post-merger P/E, use that.

Should I use ER on market price or on EPS?

Follow the question. If it lets you choose, the market price basis keeps target holders' value close to their pre-merger market value, since it matches value at current prices. The EPS basis ignores the P/E gap and shifts value between the groups, as the second example shows.