Free tool · No signup · Updates live
Merger Math:
Accretion / Dilution
The first question every board, analyst, and interviewer asks about a deal: what does it do to earnings per share? Set up the acquirer, name the price, choose the funding mix, and watch the answer move.
The deal
What it does to EPS
- Purchase price (equity)
- –
- Paid in stock / new shares
- –
- Paid with debt
- –
- After-tax interest cost
- –
- After-tax synergies
- –
- Combined net income
- –
- Combined share count
- –
What this teaches
The two classic rules of merger math are both testable here. All stock: push the funding slider to 100% stock, and the deal is accretive whenever the acquirer’s P/E is higher than the P/E it pays. You are printing expensive paper to buy cheaper earnings. All debt: push it to zero, and the deal is accretive whenever the after-tax cost of debt is below the target’s earnings yield (one divided by the P/E paid).
Then learn the trap: accretive does not mean good. Crank the P/E paid to 35x and the cost of debt down to 2%, and the model still says accretive, while the acquirer massively overpays. EPS math measures arithmetic, not value. Saying exactly that, unprompted, is what separates a good interview answer from a memorized one.
Keep going with the LBO calculator, the DCF calculator, and the M&A glossary, or see the math get people into trouble in the RJR Nabisco auction.
Questions
What is accretion and dilution?
A deal is accretive if the combined company’s earnings per share are higher than the acquirer’s standalone EPS, and dilutive if they are lower. It is the standard first-pass test of how a merger looks to the acquirer’s shareholders.
When is an all-stock deal accretive?
As a rule of thumb, an all-stock deal is accretive when the acquirer’s P/E is higher than the P/E it pays for the target. You are issuing expensive currency to buy cheaper earnings. Set the funding slider to 100 percent stock and test it.
When is a debt-funded deal accretive?
A cash/debt deal is accretive when the after-tax cost of the debt is lower than the earnings yield of the target, which is one divided by the P/E paid. Cheap debt makes almost anything look accretive, which is exactly why you should not stop at EPS math.
Does accretive mean the deal is good?
No, and this is the interview trap. Accretion measures EPS arithmetic, not value creation. Overpaying with cheap debt can be accretive and still destroy value; a dilutive deal can be a great acquisition. The math tells you how the deal screens, not whether it should happen.