Accretion vs. Dilution: How to Know If a Deal Helps or Hurts EPS

Accretion and dilution comes up in almost every M&A interview, and it rewards candidates who can do it two ways: a full calculation when asked to walk through the model, and a fast mental shortcut when the interviewer just wants to see if you understand the underlying logic. This guide covers both, along with a worked example and the follow-up questions that tend to come next.

What Accretion and Dilution Actually Measure

Accretion and dilution describe what happens to the acquirer's earnings per share after a deal closes. If pro forma EPS, meaning the combined company's EPS after the acquisition, comes out higher than the acquirer's standalone EPS before the deal, the deal is accretive. If it comes out lower, the deal is dilutive.

That's the entire concept at its core. Everything else, the P/E comparisons, the financing structure, the synergies, all feed into that one comparison between pro forma EPS and standalone EPS.

A Worked Example

Say the acquirer has $200M of net income, 100M shares outstanding, and an EPS of $2.00. Its stock trades at $50 a share, putting its P/E at 25.0x.

The target has $50M of net income and gets acquired in an all-stock deal valued at 20.0x its earnings, or $1B total. Since the acquirer's stock trades at $50 a share, financing that $1B purchase price with stock means issuing 20M new shares.

Pro forma shares outstanding come out to 120M, the acquirer's original 100M plus the 20M newly issued. Assuming no synergies for now, pro forma net income is simply the two companies added together, $200M plus $50M, or $250M. Divide that by the 120M pro forma shares, and pro forma EPS comes out to $2.08.

That's higher than the acquirer's standalone EPS of $2.00, so the deal is accretive, by a bit over 4 percent.

The Quick Way to Predict It Without Building the Model

Interviewers love asking whether you can tell if a deal is accretive or dilutive before running a single number, and there's a real shortcut for it in an all-stock deal. Compare the acquirer's P/E to the multiple it's paying for the target. If the acquirer's P/E is higher than the price paid for the target, the deal is accretive. If it's lower, the deal is dilutive.

In the example above, the acquirer trades at 25.0x and paid 20.0x for the target. Since 25.0x is higher than 20.0x, the shortcut predicts accretive, which matches the full calculation.

The intuition behind this is easier to see through earnings yield, which is just the P/E multiple flipped upside down. The acquirer's 25.0x P/E works out to a 4 percent earnings yield. The 20.0x price paid for the target works out to a 5 percent yield. Buying a 5 percent yield by issuing stock that the market only values at a 4 percent yield is, in effect, buying earnings on sale, which is exactly what accretion means in practice.

Why the Deal's Financing Changes the Answer

The P/E shortcut above applies specifically to all-stock deals. Once cash or debt enters the picture, the comparison changes, and it's worth being able to explain why rather than just knowing that it does.

For a cash-funded deal, the relevant comparison isn't the acquirer's P/E anymore, since no new shares are being issued at all. Instead, compare the target's earnings yield to the acquirer's after-tax cost of that cash, whether that's the interest rate on debt raised to fund the purchase or the interest income given up by spending cash on hand. Since borrowing costs are usually well below equity earnings yields, cash deals tend to be more accretive than stock deals financed at the same purchase price, and it's common for a deal that would be dilutive if paid in stock to turn accretive once it's funded with cash instead.

A debt-funded deal follows the same logic as cash, with one addition: the new interest expense reduces pro forma net income before it ever reaches the EPS calculation, so it's worth remembering to net that out rather than just adding the two companies' net incomes together the way the simplified stock example above did.

Where Most People Lose Points

A few patterns show up often enough to call out directly. The first is applying the P/E shortcut to a cash or debt deal, where it doesn't hold, instead of recognizing that the comparison needs to shift to a cost-of-financing basis. The second is forgetting synergies entirely, which can flip a marginally dilutive deal into an accretive one once cost savings or revenue synergies are layered in. The third is stating whether a deal is accretive or dilutive without being able to explain why in terms of the yield comparison, which is usually the actual follow-up question waiting behind the first one.

None of this requires memorizing more numbers. It comes down to understanding the yield comparison well enough to apply it to whatever financing structure gets thrown at you.

Where to Go From Here

Accretion and dilution is one of those concepts that feels abstract until you've worked through a handful of examples with different financing structures, at which point it becomes fairly mechanical. Offcycle has this exact question, along with the surrounding M&A and valuation concepts it tends to show up alongside, built into structured flashcards you can work through by topic and difficulty.

Beyond flashcards, you get custom practice sets you can build around whatever you're weakest on, quizzes that test the same material a different way, and a readiness score that tracks your progress across accounting, valuation, DCF, M&A, and LBO topics so you know exactly where you stand before you walk into the room.

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