Financial Modeling

How to Model an Acquisition in Excel: Step-by-Step Guide

By Sophal Lanh, Founder of Deal Alert AI · Updated September 05, 2026 · Start Free Trial →

Most business buyers never build an acquisition model until they're already deep in due diligence. This is a catastrophic mistake. I've analyzed 8,000+ listings across dealalertai.com and watched hundreds of acquirers either overpay by 30-40% or walk away from deals that would've generated 3x returns. The difference? They didn't model it correctly—or at all.

An acquisition model in Excel isn't some theoretical exercise. It's your financial blueprint for determining if a deal makes sense, what you should actually pay, and how you'll generate returns. Without it, you're flying blind.

This post walks you through exactly how to build one from scratch. Not the MBA textbook version—the real version I've seen work across SaaS companies, e-commerce, staffing firms, and service businesses. Specific numbers, specific formulas, specific assumptions.

Why 90% of Acquirers Model Wrong (Or Don't Model At All)

Here's the brutal truth: Most acquirers either overthink the model or skip it entirely. They see a $2M revenue business selling for $6M and think "3x multiple, that's reasonable" without understanding what's actually happening underneath. This kills deals that should get done and pushes buyers into deals that destroy value.

The real issue is that business valuations aren't just about top-line revenue. A $2M revenue business at 8% EBITDA margin ($160K profit) valued at $6M is a 37.5x multiple on earnings. A different $2M business at 35% EBITDA margin ($700K profit) at the same $6M price tag is 8.6x earnings. These are completely different deals, but most buyers don't differentiate.

Your model forces you to separate signal from noise. It answers the actual questions that matter:

Most acquirers can't answer these questions because they never built the model. They're making $500K-$5M decisions on gut feel. That's not business. That's gambling.

The Core Framework: Start With What You Know

Your model needs three core input sections: historical financials, your operating assumptions, and your exit scenario. Everything else flows from these.

Section 1: Historical Performance (Years 1-3 of your model, sometimes years 1-5)

You'll get financials from the seller. The question is: do you trust them? For most small businesses ($500K-$5M EBITDA), seller-provided statements range from "conservative and verified" to "creative accounting at best." You need to model both the seller's claim and your realistic version.

Let's say you're looking at a local digital marketing agency. Seller claims: $1.2M revenue, $420K EBITDA (35% margin). You dig into their books and find:

This is the work. This is where deals are won or lost. Your model must reflect your realistic forecast, not the seller's best case.

For your Excel sheet, create these line items:

  1. Total Revenue
  2. Cost of Goods Sold (COGS) or Cost of Services
  3. Gross Profit
  4. Gross Margin %
  5. Operating Expenses (detailed breakdown: salaries, rent, software, marketing, etc.)
  6. EBITDA
  7. EBITDA Margin %
  8. D&A (Depreciation & Amortization)
  9. EBIT
  10. Interest Expense
  11. Taxes (use realistic effective tax rate, usually 21-28% for S-Corps, 25-35% for C-Corps)
  12. Net Income
  13. Add back: D&A (non-cash)
  14. Add back: Owner adjustments (one-time items)
  15. Unlevered Free Cash Flow

That last line—unlevered free cash flow—is what actually matters. Not EBITDA, not net income. Cash. This is the money that could theoretically go to paying down debt or distributing to equity holders.

Real Example with Numbers: A staffing firm you're acquiring does $8.2M annual revenue. EBITDA is claimed at $1.23M (15% margin). When you normalize:

That extra $280K in EBITDA means on an 6x multiple, you're probably overpaying by $1.68M. This is why every line matters.

Building Your Forecast: Making Growth Assumptions That Aren't Garbage

Now you forecast forward 5-7 years. This is where most models fall apart because people either (a) assume unrealistic hockey-stick growth, or (b) assume flat revenues and wonder why they're not excited about the deal.

The key: your forecast should reflect realistic post-acquisition improvements, not fiction.

Revenue Growth Assumptions

Start with what the business has actually done. If a business has grown 8-10% annually for the last 3 years, assuming 25% growth post-acquisition better come with a concrete plan. Not "we'll add 2 sales reps" and hope. Specific initiatives with estimated contribution:

For the staffing firm example, here's a realistic model:

Notice the declining growth rate? That's reality. Most models assume 15%+ forever and look shocked when year 5 underperforms. Your model should reflect that businesses decelerate.

Margin Expansion Assumptions

This is where synergies actually matter. You might consolidate office space (save $36K/year), consolidate insurance (save $18K/year), eliminate redundant software subscriptions (save $24K/year). That's $78K in pure overhead reduction. Specific. Real. Modeled.

In your model, don't just assume margins stay flat. Build in realistic improvements:

For our staffing firm, assuming margins improve from 18.4% to 21% by year 4 due to consolidating back-office functions:

That's a 67% increase in EBITDA over 5 years from a combination of 6% blended revenue growth and margin expansion. Realistic. Achievable. Not fantasy.

The Financing Structure: How Much Debt Actually Works

Most acquirers model their deal thinking "I'll pay all cash" or "I'll get 70% debt financing" without understanding what the lender will actually allow and what makes financial sense.

Banks lending on small business acquisitions typically look at debt service coverage ratio (DSCR). Most want 1.25x minimum, with 1.5x being comfortable and 2.0x being "we can sleep at night."

DSCR = Annual EBITDA / Annual Debt Service (Principal + Interest)

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Let's say you're buying that staffing firm for $9M. Your financing options:

In your Excel model, you need:

  1. Total Purchase Price (what you're paying)
  2. Down Payment / Equity Contribution (your cash)
  3. Debt Amount (financed portion)
  4. Interest Rate (what lender is charging)
  5. Term (years to repay)
  6. Annual Principal Payment (calculated: Debt / Term)
  7. Annual Interest Payment (Debt Balance × Rate, declining as you pay down)
  8. Total Debt Service (Principal + Interest)
  9. DSCR (EBITDA / Debt Service) — must be ≥ 1.25x to keep lender happy

Create a debt paydown schedule. By year 5, your debt balance drops from $4.5M to $0. Your interest expense declines from ~$338K (year 1) to ~$68K (year 5). This compounds your cash flow.

Here's the year-by-year debt paydown on $4.5M at 7.5% over 5 years:

Now, in your cash flow forecast, you subtract the actual cash debt service (not the interest expense, which is non-cash for tax purposes but very much cash to the lender). This is levered free cash flow to equity.

Key insight: Most small business acquisitions use 40-60% debt financing. Too much debt kills your returns (you're paying interest instead of keeping cash). Too little debt wastes your opportunity to lever returns. Your model shows the exact optimal capital structure for each deal.

Calculating Your Returns: IRR, MoM, And Why Most Buyers Get It Wrong

You've built your forecast. You've layered in financing. Now: what are your actual returns?

This is where buyers make catastrophic mistakes because they don't understand the difference between IRR and cash-on-cash returns.

Metric 1: Cash-on-Cash Return (Year 1)

This is simple: Your initial equity investment divided into your year 1 cash generated.

For the staffing firm, if you put $4.5M down and the business generates $250K in year 1 levered free cash flow (after debt service), your cash-on-cash return is $250K / $4.5M = 5.6%.

That's terrible. You could get 4-5% in a bond. You're taking operational risk for 50-150 basis points of upside? Pass.

Most private equity groups want cash-on-cash returns of at least 10-15% in year 1, increasing to 20-30%+ by year 5 as debt is paid down.

Metric 2: Internal Rate of Return (IRR) — The Real Number

IRR is what you actually earned, accounting for the timing and size of all cash flows. It answers: "If I invested $4.5M today, took cash out each year, and sold the company for X in 5 years, what annual return did I achieve?"

Here's where your Excel model gets real:

The $15M sale price is critical. Let's say you sell at 6x EBITDA (your industry multiple). Year 5 EBITDA is $2.518M, so 6x = $15.108M. That's your exit value. Subtract remaining debt (which should be $0 if it's a 5-year term loan), and equity gets $15.1M.

Now your cash flows are:

Using Excel's IRR function (=IRR(array of cash flows)), this calculates to approximately 42% IRR.

That's a great deal. Most institutional acquirers target 30-35% IRR as their hurdle rate for smaller deals.

If the same deal only generated 18% IRR, you'd pass. Why? Because that's barely better than what you could achieve in public equities, with far more illiquidity and operational risk.

Metric 3: Money Multiple (MoM) — Total Return

Money multiple is simpler: Total cash returned / Total cash invested.

You invested $4.5M. You got back $250K + $385K + $575K + $815K + $16.3M = $18.325M.

MoM = $18.325M / $4.5M = 4.07x

You're turning $1 into $4.07. As a 5-year deal, this compounds to roughly 33% IRR (which matches our calculation above).

Most acquirers want 3-4x MoM minimum over 5 years. 5x MoM or higher, and the deal is home run material.

Building the IRR Calc in Excel

Here's the exact structure you need:

  1. Row 1: Year 0, Year 1, Year 2, Year 3, Year 4, Year 5
  2. Row 2: Equity Investment (-$4.5M in Year 0, $0 in all other years)
  3. Row 3: EBITDA forecasted (calculated from your revenue/margin build)
  4. Row 4: Less: Interest Expense (from debt schedule)
  5. Row 5: Less: Taxes on earnings (assume 25% effective rate)
  6. Row 6: Add back: D&A (non-cash)
  7. Row 7: Less: Principal Payment (from debt schedule)
  8. Row 8: = Levered Free Cash Flow to Equity (Row 3 - Row 4 - Row 5 + Row 6 - Row 7)
  9. Row 9: Exit Proceeds (calculated as Year 5 EBITDA × Exit Multiple, minus any remaining debt)
  10. Row 10: Total Cash Return (Row 8 + Row 9 if in exit year, just Row 8 in other years)
  11. Row 11: =IRR(all cash flows including initial investment) — this is your IRR
  12. Row 12: =MoM = (Total cash returned) / (Equity invested)

Your model is now complete on a fundamental level. But most buyers stop here and miss the most important next step.

Sensitivity Analysis: Stress-Testing Your Deal Before It Blows Up

Everything in your base case model is an assumption. Revenue growth might be 6% instead of 8%. Margins might improve 50 bps instead of 75 bps. Exit multiple might be 5x instead of 6x. What happens to your returns?

This is the question that separates good operators from lucky ones.

You need to build a sensitivity table that shows: "If revenue growth is X and exit multiple is Y, what's my IRR?"

Here's what it looks like for the staffing firm deal:

Sensitivity Table: IRR as a function of Revenue Growth Rate and Exit Multiple

Now you understand your deal's risk profile. If your thesis absolutely depends on 9% growth and a 6x exit multiple, you're taking significant risk. A 3% miss on growth drops your return from 48% to 28%. That's dangerous.

The Most Important Sensitivity: EBITDA Accuracy

Seller's claimed EBITDA is $1.51M. What if they're off by ±20%?

This is why diligence matters. That 20% variance in EBITDA ($604K) directly translates to $1.5-2M in valuation difference on a 6x multiple. Every $100K of EBITDA you uncover or verify is worth ~$600K in purchase price difference.

Create a second sensitivity table: IRR based on Normalized EBITDA (at ±10%, ±20%) and Exit Multiple (4.5x to 7x).

Your deal is robust if the IRR stays above your hurdle rate across the plausible range. It's dangerous if you need the best case to make the return work.

Build Your Sensitivity Table in Excel**

Use a two-variable data table (Excel's Data > What-If Analysis > Data Table feature). Set one variable down the rows (revenue CAGR: 2%, 4%, 6%, 8%, 10%), one across columns (exit multiple: 4.5x, 5.0x, 5.5x, 6.0x, 6.5x, 7.0x), and let Excel calculate the IRR for each combination.

The result is a 5×6 table showing IRRs across 30 scenarios. Highlight all cells above your hurdle rate in green. Cells below in red. Suddenly, you see your deal's risk clearly.

The Final Step: Purchase Price Sensitivity

Here's the question that unlocks everything: At what price does this deal hit my target IRR?

Most buyers know they want 30%+ IRR, but they don't know how to work backward to price.

Let's recalculate. If your base case assumes $1.51M EBITDA, 6% revenue growth, 6x exit multiple, you calculated 35% IRR at a $9M purchase price.

What if you wanted to achieve 35% IRR at different EBITDA scenarios?

Build this into your model. Create a column that shows: "At my target IRR (let's say 32%), what's the maximum price I should pay at each EBITDA level?"

Now you walk into negotiations knowing your number. When the seller asks $9.5M and your diligence shows $1.35M EBITDA, you know you should be around $8.1M to hit 32% IRR. You make an offer at $7.8M (25% discount to asking), they counter at $8.8M, and you settle at $8.4M. You win because you did the math.

Without this model, you're negotiating blind. You're playing poker without seeing your cards.

Practical Checklist: Building Your Model in One Sitting

  1. Step 1 - Gather Data: Collect 3 years of tax returns, P&Ls, balance sheets from the seller. Also request detail on (a) recurring vs. one-time revenue, (b) top 10 customers, (c) employee count and compensation, (d) lease terms, (e) existing debt or obligations. Without this, your model is fiction.
  2. Step 2 - Normalize Historical EBITDA: Take the past 12 months or last full year. Remove one-time items (litigation, equipment sales, etc.). Adjust for owner discretionary expenses (add back excess compensation, related-party payments, personal expenses). Calculate real EBITDA and margin. This is your starting point, not the seller's claim.
  3. Step 3 - Build Revenue Forecast: Project 5-7 years forward. Year 1 should be conservative (integration risk). Years 2-5 should reflect realistic growth tied to specific initiatives. Terminal growth should decelerate to 3-5% (GDP-ish). Build in sensitivity to what happens if growth is -2 to +3% different.
  4. Step 4 - Project Margins: Model gradual margin expansion from operational improvements. Don't assume flat margins forever (boring, unrealistic) or massive jumps (scary, unbelievable). Show year-by-year expansion based on specific cost savings or scale benefits. Calculate EBITDA for each year.
  5. Step 5 - Layer in Financing:** Determine how much debt you can support based on DSCR (aim for 1.3-1.5x minimum in year 1). Build debt paydown schedule showing principal and interest each year. Calculate levered free cash flow (EBITDA - Interest - Taxes - Principal) to equity each year.
  6. Step 6 - Calculate IRR and Money Multiple: Set your exit multiple (typically 5.5-6.5x EBITDA for small businesses). Calculate sale proceeds in exit year (year 5 or 6). Set initial equity investment as negative cash flow in year 0. Use IRR formula on all cash flows. Calculate money multiple as total cash returned / cash invested.
  7. Step 7 - Build Sensitivity Tables: Create two-variable tables showing IRR across ranges of (a) revenue CAGR and exit multiple, (b) normalized EBITDA and exit multiple, (c) purchase price and exit multiple. Identify which variables matter most to your return. Test what happens if your worst-case assumption materializes.
  8. Step 8 - Calculate Maximum Purchase Price: Work backward from your target IRR. At different normalized EBITDA levels, what's the maximum price you should pay? Use this as your negotiation anchor.
  9. Step 9 - Pressure Test Against Market:** Pull 10-20 recent acquisitions in the industry from dealalertai.com or other sources. What multiples are deals getting? What growth rates are being paid for? Is your deal priced in line, or are you overpaying for underperformance? Reality-check your assumptions against market.
  10. Step 10 - Document Assumptions:** Write down every assumption in a separate tab. Revenue growth rates, margin expansion, exit multiple, tax rate, discount rate, everything. When you update the model 3 months from now, you need to know what you assumed and why. Future you will thank current you.

Real Deal Example: Putting It All Together

Let's walk through an actual acquisition model for a business that appears in the $2-5M EBITDA range.

The Business: Regional plumbing contractor. $3.8M annual revenue. Seller claims $912K EBITDA (24% margin). Currently owner-operated, owner takes $180K salary plus $95K in "perks" (vehicle, fuel, phone, etc.).

Step 1 - Normalize EBITDA**

Step 2 - Determine Financing

You want to acquire this business. Your target: 32% IRR over 5 years. You're putting down $1.5M equity. How much debt can you support?

Year 1 normalized EBITDA: $1.082M. Lender wants 1.3x minimum DSCR.