# How to Build a Merger Model (M&A Model) in Excel *Alex Tapio · 2026-07-11 · 14 min · Model Deep-Dives* Canonical: https://finamodel.com/blog/merger-model-guide A step-by-step guide to building a merger model in Excel: value the target, set the offer price, structure the financing, combine the income statements, and calculate EPS accretion/dilution with synergies and a sensitivity table. **A merger model is the tool investment bankers and corporate development teams use to answer one question: will this acquisition make the buyer's shareholders richer or poorer? The headline output is EPS accretion/dilution - whether the combined company's earnings per share rise or fall versus the acquirer standalone. This guide walks through the full build in Excel: valuing the target, setting the offer price, structuring the cash/stock/debt financing, combining the income statements, layering in synergies, and stress-testing the answer with a sensitivity table - all with a fully worked numerical example.** A merger model (also called an M&A model) sits alongside the DCF and the LBO as one of the three core valuation and deal frameworks in finance. Where a DCF asks *what is this company worth?* and an LBO asks *what return can a sponsor earn?*, a merger model asks *what happens to the acquirer's earnings per share if it buys this target?* That per-share lens is what makes it distinctive - a strategic buyer folds the target into its own income statement, and the market judges the deal on the resulting EPS. The mechanics are less about elaborate forecasting and more about getting the plumbing right: the offer price and premium, the mix of cash, stock and new debt used to pay for it, the synergies that justify the premium, and the after-tax cost of the financing. Miss any one of those and your accretion number is wrong. ```mermaid flowchart TD A["Value the Target DCF Comps Precedents"] --> B["Set Offer Price and Premium"] B --> C["Choose Financing Cash Stock Debt Mix"] C --> D["Combine Acquirer and Target Net Income"] D --> E["Add After-Tax Synergies Subtract New Interest"] E --> F["Divide by Pro Forma Share Count"] F --> G["Pro Forma EPS vs Acquirer Standalone EPS"] G --> H["Accretive if Higher Dilutive if Lower"] ``` *The merger model build flow: from target valuation to the accretion/dilution verdict.* --- ## What a Merger Model Actually Computes Stripped to its core, a merger model does five things: 1. **Values the target** using DCF, trading comparables, and precedent transactions to establish a defensible price range. 2. **Sets the offer** - a price per share, expressed as a premium over the target's unaffected share price. 3. **Structures the financing** - how much of the purchase is paid in cash, new debt, and newly issued acquirer stock. 4. **Combines the income statements** - adds the two companies' earnings, adjusts for synergies and the after-tax cost of financing. 5. **Computes accretion/dilution** - divides pro forma net income by the new share count and compares the result to the acquirer's standalone EPS. As with any model, the golden rule holds: every input lives on an `Assumptions` sheet and every formula references it. Never hardcode a premium, an interest rate, or a synergy figure inside a calculation cell. --- ## Step 1: Value the Target Before you can set an offer price you need a view on what the target is worth. A credible merger model triangulates three methods and presents them as a "football field" range: | Valuation Method | Low | High | | :--- | :---: | :---: | | DCF (WACC ~9%) | $1,050M | $1,150M | | Trading Comparables (EV/EBITDA) | $980M | $1,120M | | Precedent Transactions | $1,150M | $1,350M | The DCF anchors the intrinsic value; trading comps show where public peers trade today; precedent transactions capture what acquirers have actually paid for similar businesses (and therefore embed a control premium). The offer price will typically land toward the top of, or above, the standalone ranges - because the buyer must pay a premium to gain control. The discount rate for the target's standalone DCF is its WACC. If you want to sanity-check a cost of capital before dropping it into the model, run the numbers here: For the full mechanics of the standalone valuation, see the [DCF model tutorial](/blog/dcf-model-excel-tutorial) and the guide to [comparable company analysis](/blog/comparable-company-analysis). --- ## Step 2: Set the Offer Price and Premium With a valuation range in hand, set the offer. Assume the target trades at an unaffected price of **$25.00** per share with **40M** shares outstanding - a standalone equity value of **$1,000M**. The acquirer offers **$30.00** per share: ``` Premium = (Offer Price / Unaffected Price) - 1 Premium = ($30.00 / $25.00) - 1 = 20.0% Offer Equity Value = Offer Price × Target Shares Offer Equity Value = $30.00 × 40M = $1,200M ``` A 20% premium is typical for a public-company acquisition. The $1,200M offer sits inside the precedent-transaction range above, so it is defensible. One number to carry forward - the **deal P/E**, the multiple of the target's earnings the acquirer is paying: ``` Deal P/E = Offer Equity Value / Target Net Income Deal P/E = $1,200M / $50M = 24.0x ``` --- ## Step 3: Structure the Financing The acquirer must fund $1,200M. There are three sources: **cash on hand**, **new debt**, and **newly issued acquirer stock**. The mix drives the accretion answer, so it is the single most important modelling choice. For the base case, assume a **50% stock / 50% cash** structure, with the cash portion funded entirely by new debt: | Source | Amount | Detail | | :--- | :---: | :--- | | New acquirer stock | $600M | Issued at $40.00/share = 15.0M new shares | | New debt (funds cash portion) | $600M | Interest rate 6.0% | | **Total consideration** | **$1,200M** | - | ```excel // New shares issued to fund the stock portion = Stock_Consideration / Acquirer_Share_Price = $600M / $40.00 = 15.0M shares // Interest on the new acquisition debt (pre-tax) = New_Debt * Cost_of_Debt = $600M * 6.0% = $36.0M ``` The key insight: stock financing dilutes the *denominator* (more shares), while debt financing reduces the *numerator* (after-tax interest expense). Which hurts less depends on the acquirer's P/E versus its after-tax cost of debt. --- ## Step 4: Combine the Income Statements Now assemble the pro forma income statement. Here are the two companies' standalone figures: | Metric | Acquirer | Target | | :--- | :---: | :---: | | Net Income | $200M | $50M | | Shares Outstanding | 100M | 40M | | **EPS** | **$2.00** | **$1.25** | | Share Price | $40.00 | $25.00 | | Standalone P/E | 20.0x | 20.0x | The combined net income starts as the simple sum, then adjusts for the after-tax cost of the new debt. Tax rate is **25%**. ```excel // After-tax interest on new debt = New_Interest * (1 - Tax_Rate) = $36.0M * (1 - 0.25) = $27.0M // Pro forma net income (base case, before synergies) = Acquirer_NI + Target_NI - Aftertax_Interest = $200M + $50M - $27.0M = $223.0M // Pro forma share count = Acquirer_Shares + New_Shares_Issued = 100M + 15.0M = 115.0M ``` **Base case pro forma EPS (no synergies):** ``` Pro Forma EPS = Pro Forma Net Income / Pro Forma Shares Pro Forma EPS = $223.0M / 115.0M = $1.94 ``` Compare to the acquirer's $2.00 standalone EPS: ``` Accretion/(Dilution) = ($223.0M / 115.0M) / ($200M / 100M) - 1 = $1.94 / $2.00 - 1 = -3.0% ``` The deal is **3.0% dilutive** before synergies. That is the honest starting point - the premium and the financing cost outweigh the earnings the acquirer is buying. --- ## Step 5: Add Synergies - and the Breakeven Test Synergies are the reason the acquirer is willing to pay a premium. Assume **$30M of pre-tax annual cost synergies** (headcount, procurement, overhead). On an after-tax basis: ```excel // After-tax synergies = Pretax_Synergies * (1 - Tax_Rate) = $30.0M * (1 - 0.25) = $22.5M // Pro forma net income (with synergies) = Acquirer_NI + Target_NI + Aftertax_Synergies - Aftertax_Interest = $200M + $50M + $22.5M - $27.0M = $245.5M ``` **Pro forma EPS with synergies:** ``` Pro Forma EPS = $245.5M / 115.0M = $2.13 Accretion = ($245.5M / 115.0M) / ($200M / 100M) - 1 = +6.7% ``` The $22.5M of after-tax synergies flip the deal from 3.0% dilutive to **6.7% accretive**. This is the whole game: the premium is only justified if synergies more than offset the dilution. ### The Breakeven Synergy Level The most useful single number to present to a board is the level of synergies that keeps EPS flat - the point where the deal is neither accretive nor dilutive: ```excel // Pre-tax synergies needed for breakeven (EPS = acquirer standalone) = (Acquirer_EPS * Proforma_Shares - (Acquirer_NI + Target_NI - Aftertax_Interest)) / (1 - Tax_Rate) = ($2.00 * 115.0M - $223.0M) / (1 - 0.25) = ($230.0M - $223.0M) / 0.75 = $7.0M / 0.75 = $9.3M ``` Only **~$9.3M of pre-tax synergies** are needed just to break even - against a $30M target, that leaves a comfortable cushion. If management could only credibly defend $8M of synergies, the deal would stay dilutive and the offer price would need to come down. --- ## The Quick P/E Rule of Thumb Before building the full model, seasoned bankers estimate accretion/dilution in their head using P/E multiples. It is worth internalising because it explains *why* the numbers come out the way they do. **All-stock leg:** A stock-funded deal is accretive when the acquirer's P/E exceeds the deal P/E it pays for the target. ``` Acquirer P/E = 20.0x Deal P/E paid = 24.0x 20.0x < 24.0x → the stock-funded portion is DILUTIVE ``` You are issuing 20x-P/E stock to buy earnings at 24x - expensive currency for cheap-relative earnings, so it dilutes. **Cash/debt leg:** A debt-funded deal is accretive when the target's earnings yield exceeds the after-tax cost of debt. ``` Target earnings yield = 1 / Deal P/E = 1 / 24.0x = 4.17% After-tax cost of debt = 6.0% × (1 - 0.25) = 4.50% 4.17% < 4.50% → the debt-funded portion is (slightly) DILUTIVE ``` Both legs are mildly dilutive, which is exactly why the full model returned −3.0% before synergies. The rule of thumb and the full build agree - always a good sign your plumbing is correct. Download a ready-built M&A model - with the standalone valuation, deal structure, synergies, and accretion/dilution already wired up - and reverse-engineer the formulas: --- ## Sensitivity Analysis: Financing Mix × Synergies A single accretion number is fragile. The two assumptions that move it most are the **financing mix** (how much stock vs. cash/debt) and the **synergy level**. Build a two-way table showing pro forma accretion/(dilution) across both. | % Stock \\ Pre-Tax Synergies | $0M | $15M | $30M | $45M | | :--- | :---: | :---: | :---: | :---: | | **0% (all cash/debt)** | −2.0% | +3.6% | +9.3% | +14.9% | | **25% stock** | −2.6% | +2.7% | +7.9% | +13.1% | | **50% stock** | −3.0% | +1.8% | **+6.7%** | +11.6% | | **75% stock** | −3.5% | +1.1% | +5.7% | +10.3% | | **100% (all stock)** | −3.8% | +0.5% | +4.8% | +9.1% | The base case (50% stock, $30M synergies) sits at **+6.7%**, shown in bold. ### Reading the Table - **Cash is less dilutive than stock here.** Moving along the $0M column, all-cash is −2.0% while all-stock is −3.8%. That is because after-tax debt (4.5%) is only just above the target's earnings yield (4.17%), whereas issuing 20x-P/E stock to buy 24x earnings dilutes more. When cash/debt is cheap, prefer it - up to the leverage the balance sheet can bear. - **Synergies dominate the outcome.** Every $15M of pre-tax synergies adds roughly 5 percentage points of accretion. Even the all-stock structure turns accretive at ~$15M of synergies. - **The deal is robust.** At the $30M synergy target, every financing mix is comfortably accretive (+4.8% to +9.3%). The risk is on the synergy axis, not the financing axis - which tells management where to focus diligence. --- ## Common Mistakes to Avoid 1. **Forgetting the after-tax cost of financing.** New acquisition debt carries interest, and new shares dilute the count. Omitting either - or forgetting to tax-affect the interest - overstates accretion. Always net the after-tax interest against combined earnings. 2. **Treating gross synergies as free.** Synergies come with one-time integration costs (severance, systems migration, advisory fees). Model those costs explicitly and phase synergies in over 2–3 years rather than assuming they land in full on day one. 3. **Ignoring the premium.** The bigger the premium, the higher the deal P/E, and the harder it is to be accretive. A strategically sound target bought at too high a premium can still be dilutive - the model must let you flex the offer price. 4. **Confusing accretion with value creation.** A deal can be accretive (boosts EPS) yet still destroy value if the acquirer overpays relative to the target's intrinsic worth. Accretion is a first-pass screen, not a substitute for a proper valuation. A cheap-debt-funded deal almost always looks accretive; that does not make it wise. 5. **Using a single point estimate.** Never present one accretion number. Show the sensitivity table across financing mix and synergies, and always highlight the breakeven synergy level so the board knows how much has to go right. 6. **Mismatching the share price for new equity.** New shares are issued at the acquirer's current (unaffected) share price, not a random figure. Link the new-share calculation to the same price cell used elsewhere in the model. --- ## Key Takeaways - **The headline output is EPS accretion/dilution.** A merger model combines acquirer and target earnings, adjusts for synergies and after-tax financing costs, and divides by the new share count - then compares pro forma EPS to the acquirer's standalone EPS. - **Financing mix drives the answer.** Stock dilutes the share count; debt reduces earnings via after-tax interest. Cash/debt is often less dilutive than stock, but adds leverage - the model must weigh both. - **Synergies justify the premium.** Layer them in after-tax, phase them realistically, and always compute the breakeven synergy level - the amount needed just to keep EPS flat. In the worked example, ~$9.3M of pre-tax synergies breaks even against a $30M target. - **Use the P/E rule of thumb to sanity-check.** All-stock is accretive when acquirer P/E > deal P/E; cash/debt is accretive when the target's earnings yield > after-tax cost of debt. If the full model disagrees with the rule of thumb, your plumbing is broken. - **Accretion is not value creation.** An accretive deal can still overpay and destroy value. Anchor the offer price in a proper standalone valuation (DCF, comps, precedents) before judging the deal on EPS. - **Never present a point estimate.** Build a two-way sensitivity table across financing mix and synergies, highlight the base case, and frame the verdict as a range. To see how the merger model compares with the other two core deal frameworks, read [DCF vs LBO vs 3-Statement](/blog/dcf-vs-lbo-vs-3-statement), and for the standalone earnings-impact mechanics in more depth, see [accretion/dilution analysis in M&A](/blog/accretion-dilution-analysis) and the [LBO model tutorial](/blog/lbo-model-tutorial). You can also grab the free [M&A model template](/templates/ma) to start from a working build. ## Frequently asked questions ### What is a merger model? A merger model (or M&A model) combines the financials of an acquirer and a target to test whether a proposed acquisition creates or destroys value for the acquirer's shareholders. Its headline output is accretion/dilution: whether pro forma earnings per share (EPS) after the deal are higher (accretive) or lower (dilutive) than the acquirer's standalone EPS. A full model also values the target, sets the offer price and premium, structures the financing (cash, stock, or debt), layers in synergies and integration costs, and stress-tests the result with a sensitivity table. ### What is the difference between a merger model and an LBO model? A merger model is built from the perspective of a strategic (corporate) acquirer buying a target and folding it into its own income statement - the key output is EPS accretion/dilution. An LBO model is built from the perspective of a financial sponsor (private equity) that buys a company with heavy debt, holds it for ~5 years, and sells it - the key output is the equity IRR and MOIC (multiple on invested capital). Merger models care about the acquirer's per-share earnings; LBO models care about the fund's return on invested equity. ### What does accretion/dilution mean? Accretion means the deal increases the acquirer's pro forma EPS relative to its standalone EPS; dilution means it decreases it. You compute it by combining the two companies' net income, adding after-tax synergies, subtracting the after-tax cost of any new financing (interest on acquisition debt), and dividing by the new pro forma share count (which rises if the acquirer issues stock to pay for the deal). If pro forma EPS is above standalone EPS the deal is accretive; if below, dilutive. Accretion is not the same as value creation, but boards and investors watch it closely as a first-pass screen. ### Is a cash deal or a stock deal more accretive? It depends on the relative cost of each financing source versus the earnings yield you are buying. A quick 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 (buying cheaper earnings with expensive stock). A cash/debt-funded deal is accretive when the target's earnings yield exceeds the after-tax cost of debt. Because cash and debt are usually 'cheaper' than issuing equity, cash deals are often less dilutive than stock deals - but they add leverage and financial risk, which the model must also weigh. ### How do synergies affect accretion/dilution? Synergies - cost savings (headcount, procurement, overhead) or revenue uplift (cross-sell, new geographies) - flow straight into pro forma net income on an after-tax basis, so they push a deal toward accretion. A deal that is dilutive on a standalone basis can become accretive once realistic synergies are included. The critical discipline is to model synergies conservatively, phase them in over time (they rarely arrive on day one), and net out one-time integration costs. Always show the breakeven synergy level: the amount of synergies needed just to keep EPS flat. ### What are the most common mistakes in a merger model? The biggest errors are: (1) forgetting the after-tax cost of acquisition debt or the new shares issued, which flatters accretion; (2) treating gross synergies as if they were free and ignoring integration costs; (3) assuming synergies arrive fully in year one instead of ramping; (4) ignoring the premium paid - overpaying can make even a strategically sound deal dilutive; (5) confusing accretion with value creation (an accretive deal financed with cheap debt can still destroy value if the price is too high); and (6) presenting a single point estimate instead of a sensitivity table across financing mix and synergy assumptions.