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Accretion/Dilution Analysis: What It Is and How to Explain It in Interviews

8 min read

Key takeaways
  • A deal is accretive if post-deal EPS exceeds standalone EPS; dilutive if it decreases
  • In cash deals, accretion depends on target earnings vs. after-tax financing cost; in stock deals, it depends on relative P/E ratios
  • An accretive deal is not always a good deal — accretion is a short-term metric that ignores long-term value
  • The five-step calculation: standalone EPS, pro-forma NI, pro-forma shares, pro-forma EPS, and the percentage change

What Accretion/Dilution Measures

Accretion/dilution analysis tells you whether a deal increases or decreases the acquirer's earnings per share (EPS). If post-deal EPS is higher than standalone EPS, the deal is accretive. If lower, it is dilutive.

This matters because boards and shareholders care about whether an acquisition will improve or harm the acquirer's near-term profitability.


The Core Logic

Deal TypeWhat Drives AccretionKey Test
Cash dealTarget earnings vs. after-tax financing costDoes the target earn more than the cost of the debt used to buy it?
Stock dealRelative P/E ratiosIs the acquirer's P/E higher than the target's? (Buying cheap earnings with expensive shares)

Step-by-Step Calculation

Step 1: Calculate acquirer standalone EPS: Net Income / Shares Outstanding
Step 2: Calculate pro-forma combined Net Income: Acquirer NI + Target NI + Synergies - Transaction Costs - New Interest Expense - Intangible Amortisation (tax-adjusted)
Step 3: Calculate pro-forma shares: Acquirer shares + New shares issued (if stock deal)
Step 4: Pro-forma EPS = Pro-forma NI / Pro-forma Shares
Step 5: Accretion/Dilution = (Pro-forma EPS - Standalone EPS) / Standalone EPS
Accretion/Dilution % = (Pro-forma EPS - Standalone EPS) / Standalone EPS

Worked Example

Acquirer: Net Income £270M, 500M shares → Standalone EPS = £0.54

Target: Net Income £65M. Acquirer issues 36M new shares and takes on £38M new annual interest. Synergies add £27M to combined NI. Intangible amortisation reduces NI by £6M (after tax).

Pro-forma NI: £270M + £65M + £27M - £38M - £6M = £318M

Pro-forma Shares: 500M + 36M = 536M

Pro-forma EPS: £318M / 536M = £0.593

+9.8% Accretive — pro-forma EPS of £0.593 exceeds standalone EPS of £0.54

Common Interview Questions

Key insight An accretive deal is not always a good deal. Accretion is a short-term metric. A deal can be accretive but destroy long-term value if the acquirer overpays or synergies do not materialise. Conversely, a dilutive deal can create value if it positions the acquirer strategically.

"Is an accretive deal always a good deal?" — No. Accretion is a short-term metric. A deal can be accretive but destroy long-term value if the acquirer overpays or synergies do not materialise. Conversely, a dilutive deal can create value if it positions the acquirer strategically.

"What makes a stock deal more likely to be dilutive?" — When the acquirer's P/E is lower than the target's. You are issuing expensive shares (in P/E terms) to buy expensive earnings. The math works against you.

Take Your Preparation Further

Build and analyse a full merger model with our Merger Model Template — includes PPA, synergies, and accretion/dilution analysis. For comprehensive interview prep, see the IB Interview Bible.

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