LBO Modelling Explained: Complete Guide for IB & PE Interviews

The leveraged buyout is one of the most tested topics in both investment banking and private equity interviews. The LBO combines valuation, capital structure, and financial modelling into one framework. If you can explain how an LBO works and run a paper LBO, you're in strong shape for any technical interview.

What Is an LBO?

A leveraged buyout is when a private equity firm acquires a company using a significant amount of debt (leverage) alongside a smaller amount of equity. The PE firm operates the company for several years, uses its cash flows to pay down debt, and eventually sells the company at a profit.

The key insight: leverage amplifies returns. If you buy a company for £100m using £70m of debt and £30m of equity, and sell it for £150m after paying off all the debt, your equity return is £80m on a £30m investment – a 2.7x return. Without leverage, you'd have invested £100m to make £50m – only 1.5x.

Key LBO Mechanics

Sources & Uses

Every LBO starts with a Sources & Uses table. Uses: the purchase price of the company plus any transaction fees and expenses. Sources: how the purchase is funded – different tranches of debt (senior, subordinated, mezzanine) plus the equity contribution from the PE firm. Sources must equal Uses.

Debt Structure

LBOs typically layer multiple types of debt:

Senior Debt (Bank Debt): Cheapest, highest priority in bankruptcy. Usually 3–5x EBITDA. Often has mandatory amortisation (repaid over time from cash flows).

High-Yield Bonds / Subordinated Debt: More expensive, lower priority. Typically bullet maturity (repaid all at once at maturity). Fills the gap between senior debt and equity.

Mezzanine / Preferred Equity: Most expensive debt-like instrument. Sometimes includes equity warrants. Used when more leverage is needed.

Total leverage in an LBO is typically 4–6x EBITDA, though this varies by market conditions and the target company's stability.

The Hold Period

PE firms typically hold investments for 3–7 years (5 years is the standard assumption for interviews). During this period, the company's cash flows service debt and pay it down, EBITDA grows through operational improvements, and the PE firm works to increase the company's value.

The Three Value Creation Levers

PE firms create returns through three mechanisms, and interviewers will ask you about all of them:

1. EBITDA Growth: Growing the company's earnings through revenue increases, margin improvements, cost-cutting, or operational efficiency. This directly increases the exit value.

2. Multiple Expansion: Buying at a lower multiple and selling at a higher one. If you buy at 7x EBITDA and sell at 9x, you've created value just from the market rerating the business. This isn't always within the PE firm's control – it depends on market conditions.

3. Debt Paydown: As the company repays debt with its cash flows, more of the enterprise value belongs to equity. Even if the company's value stays flat, the equity value increases as debt decreases. This is the 'free' return from leverage.

Returns: IRR and MOIC

MOIC (Multiple of Invested Capital): Exit Equity / Entry Equity. If you invested £30m and got back £90m, that's a 3.0x MOIC. Simple, intuitive, but ignores time.

IRR (Internal Rate of Return): The annualised return that accounts for timing. A 3.0x MOIC in 5 years is roughly a 25% IRR. A 3.0x MOIC in 3 years is roughly a 44% IRR. Time matters enormously.

PE firms typically target a minimum of 20–25% IRR and 2.0–3.0x MOIC. Quick IRR approximations: 2x in 3 years ≈ 26%, 2x in 5 years ≈ 15%, 3x in 5 years ≈ 25%.

What Makes a Good LBO Candidate?

Not every company works as an LBO target. The ideal characteristics:

• Stable, predictable cash flows: The company needs to service significant debt, so cash flow stability is critical. Cyclical businesses are risky.
• Strong market position: Ideally a market leader or in a niche with defensible competitive advantages.
• Low CapEx requirements: More free cash flow available for debt repayment. Asset-light businesses are attractive.
• Tangible assets (for collateral): Lenders prefer companies with real assets they can claim in bankruptcy. Useful for securing cheaper debt.
• Cost-cutting opportunities: PE firms look for operational improvements they can make – underperforming management, bloated cost structures, or inefficient operations.
• Fragmented industry: Opportunity for buy-and-build strategies – acquiring and rolling up smaller competitors.

How to Answer 'Walk Me Through an LBO'

In a leveraged buyout, a PE firm acquires a company using a mix of debt and equity. You start by calculating the purchase price based on an entry multiple times EBITDA. Then you build a Sources & Uses table to determine how much debt and equity is needed. Over a 5-year hold period, you project the company's cash flows and use them to pay down debt. At exit, you calculate the enterprise value using an exit multiple, subtract remaining debt to get equity value, and compare that to the initial equity invested. Returns are measured by MOIC and IRR. Value is created through three levers: EBITDA growth, multiple expansion, and debt paydown.