What Is a Merger Model?
A merger model combines the financial statements of an acquirer and a target to show what the combined company looks like after a deal. Its headline output is accretion or dilution: whether the acquirer's earnings per share rises or falls on a pro forma basis. Alongside EPS, the model shows the combined company's leverage and credit profile, how much each side contributes to the whole, and how sensitive the outcome is to price, financing mix, and synergies.
Bankers build merger models on both sides of a deal. On the buy side, the model tests what the client can afford to pay, how to finance the purchase, and what the deal does to earnings and ratings. On the sell side, it demonstrates what a buyer could justify paying. The same mechanics feed board materials and fairness opinion work, which is why the merger model sits with the DCF and the LBO model as core analyst skills.
How to Build a Merger Model Step by Step
- Step 1: Build or collect standalone projections for the acquirer and the target, typically three to five years of income statement detail at minimum
- Step 2: Set the transaction assumptions: offer price per share and the implied premium, the consideration mix across cash, stock, and debt, and advisory and financing fees
- Step 3: Build the sources and uses table so every dollar of purchase price and fees is funded by a specific source
- Step 4: Allocate the purchase price: write the target's assets up to fair value, create identifiable intangibles, and record the remainder as goodwill
- Step 5: Make the pro forma adjustments: new interest expense on acquisition debt, foregone interest income on cash used, amortization of new intangibles, and synergies with their phase-in schedule
- Step 6: Combine the income statements line by line and apply the combined tax rate to reach pro forma net income
- Step 7: Compute the new share count: existing acquirer shares plus any shares issued as stock consideration, where new shares equal the stock consideration divided by the acquirer's share price
- Step 8: Divide pro forma net income by the pro forma share count to get pro forma EPS, and compare it to the acquirer's standalone EPS
- Step 9: Layer on sensitivities for price, financing mix, and synergies, and check pro forma credit metrics such as debt/EBITDA and interest coverage
Accretion / Dilution Math
Pro forma EPS = (acquirer net income + target net income + after-tax synergies - after-tax transaction adjustments) / (acquirer shares + new shares issued). The adjustments are the after-tax cost of the financing: new interest expense on deal debt, foregone interest income on cash spent, and incremental amortization from intangible write-ups. If pro forma EPS exceeds the acquirer's standalone EPS, the deal is accretive. If it is lower, the deal is dilutive.
The rule of thumb compares the target's earnings yield to the cost of the money used to buy it. Earnings yield is the inverse of the purchase P/E: target net income divided by the equity purchase price. For a cash or debt funded deal, the transaction is accretive when the target's earnings yield exceeds the after-tax cost of the cash or debt. For an all-stock deal, it collapses into a P/E comparison: the deal is accretive when the acquirer's P/E is higher than the P/E it pays for the target, because the acquirer is issuing richly valued currency in exchange for cheaper earnings. For mixed consideration, blend the after-tax cost of each source by its weight and compare that blended rate to the target's earnings yield.
The rule ignores synergies, intangible amortization, and fees, so treat it as a first-cut screen. It tells you the direction of the answer before you build anything.
Sources and Uses
The sources and uses table forces the financing to balance. Uses include the equity purchase price, which is the offer per share times the target's diluted shares, plus repayment of target debt that does not survive the deal (change of control provisions usually force refinancing), plus transaction fees. Sources include new debt raised, cash from the acquirer's balance sheet, and stock issued to the target's shareholders. Total sources must equal total uses.
The table is more than bookkeeping. The mix chosen here drives everything downstream: each dollar of debt adds interest expense, each dollar of cash gives up interest income, and each dollar of stock adds shares to the denominator. It also sets pro forma leverage, which determines whether the structure is realistic for the acquirer's credit rating and covenant capacity.
Key Assumptions That Drive the Output
Three assumptions dominate the result.
The premium. A higher offer price raises the purchase P/E, which lowers the target's earnings yield and pushes the deal toward dilution. It also creates more goodwill and intangibles, and more amortization where intangibles are written up.
The financing mix. Debt is usually the cheapest source on an after-tax basis, and cash is close behind, since its cost is only the after-tax interest income given up. The cost of stock is the acquirer's own earnings yield: a highly valued acquirer has an inexpensive acquisition currency, while a cheaply valued acquirer will find stock deals dilutive. The mix trades EPS against balance sheet risk, because maximizing debt minimizes dilution but raises leverage and can threaten ratings.
Synergies. After-tax synergies add directly to pro forma net income and can flip a dilutive deal to accretive. Models therefore show results with and without synergies and calculate breakeven synergies, the annual amount needed to make the deal EPS-neutral.
Also worth flagging: the tax rate, the synergy phase-in schedule, and whether one-time integration costs are included in adjusted EPS all move the answer at the margin.
Worked Mini Example
Suppose an acquirer earns $1,000M of net income with 500M shares outstanding, so standalone EPS is $2.00. It buys a target earning $200M of net income for $3,600M in cash, an 18x purchase P/E, funded entirely with new debt at 6% pre-tax. At a 25% tax rate, after-tax interest expense is $3,600M × 6% × 0.75 = $162M.
Pro forma net income = $1,000M + $200M - $162M = $1,038M. No shares were issued, so pro forma EPS = $1,038M / 500M = $2.08 versus $2.00 standalone, roughly 4% accretive.
Check it against the rule of thumb: the target's earnings yield is $200M / $3,600M = 5.6%, which beats the 4.5% after-tax cost of debt, so the deal had to come out accretive. Add $30M of after-tax synergies and pro forma EPS rises to about $2.14, roughly 7% accretive.
Merger Model Questions Interviewers Ask
- Walk me through a merger model from start to finish: compress the nine steps above into 60-90 seconds
- What makes a deal accretive or dilutive, and what is the quick rule of thumb
- Why might an accretive deal still be a bad deal: EPS math says nothing about whether the price paid exceeds intrinsic value, and cheap debt can make overpaying look good
- How does an all-stock deal differ from an all-cash deal in the model
- What are breakeven synergies and how would you solve for them
- Where does goodwill come from in the model and why does it exist
- If the acquirer trades at 20x earnings and pays 25x for the target in an all-stock deal, what happens: dilutive, and be ready to explain the earnings yield logic behind it
Fluency here signals that you understand both the mechanics and the judgment. The model measures EPS impact, and EPS impact is not the same thing as value creation. Saying that unprompted is one of the easiest ways to stand out in a technical round.