How to Build a 3-Statement Financial Model | Step-by-Step

Key takeaways

The 3-statement model is the foundation of all financial modelling — DCFs, LBOs, and merger models all start here
The three statements are dynamically linked: changes in the IS flow to retained earnings (BS) and operating cash flow (CFS)
Build in five steps: assumptions, income statement, balance sheet, cash flow statement, then balance check
If the balance sheet does not balance, trace the error through your linkages — the most common cause is a missing working capital adjustment

What Is a 3-Statement Model?

A 3-statement financial model projects a company's income statement, balance sheet, and cash flow statement over a forecast period (typically 5 years). It is the foundation that feeds into every other model — DCFs, LBOs, and merger models all start here.

The key concept: the three statements are dynamically linked. A change in revenue flows through to net income (IS), retained earnings (BS), and operating cash flow (CFS). If your balance sheet does not balance, there is an error in your linkages.

How the Three Statements Link

Link	From	To	How
IS → BS	Net Income	Retained Earnings	Net of dividends paid
IS → CFS	Net Income	Starting point of CFO	D&A added back (non-cash)
CFS → BS	Ending Cash	Cash line on BS	Capex increases PP&E; debt changes update BS

Building the Model: Step by Step

Step 1 — Assumptions: Revenue growth, margins (gross, EBITDA, EBIT), D&A as % of revenue, capex, working capital days (DSO, DIO, DPO), tax rate, interest rate.

Step 2 — Income Statement: Revenue → COGS → Gross Profit → SG&A → EBITDA → D&A → EBIT → Interest → EBT → Tax → Net Income. Every line should reference your assumptions.

Step 3 — Balance Sheet: Calculate AR, inventory, and AP from working capital days. Calculate PP&E from prior PP&E + capex - D&A. Retained earnings = prior RE + net income - dividends.

Step 4 — Cash Flow Statement: Start with net income, add back D&A, adjust for working capital changes (increase in AR = cash outflow; increase in AP = cash inflow), subtract capex, add/subtract debt and equity changes.

Step 5 — Balance check: Total Assets must equal Total Liabilities + Equity. If it does not, trace the error through your linkages.

Common Errors

Common mistake The circular reference trap: interest expense depends on debt balance, which depends on cash flow, which depends on interest expense. Break this with an iterative calculation or a debt plug.

Balance sheet does not balance: Usually caused by missing a working capital adjustment or forgetting to link ending cash to the BS.

Circular reference: Interest expense depends on debt balance, which depends on cash flow, which depends on interest expense. Break this with an iterative calculation or a debt plug.

Key insight In a growing company, capex should exceed D&A (PP&E is growing). If D&A exceeds capex, the company is harvesting its asset base — which is unsustainable long-term.

Capex and D&A disconnected: In a growing company, capex should exceed D&A (PP&E is growing). If D&A exceeds capex, the company is harvesting its asset base — which is unsustainable.

Take Your Preparation Further

Download our free Accounting Cheat Sheet for the complete three-statement linkage reference. For a hands-on model with all linkages built, see the 3-Statement Financial Model.

For the timed-exam version of this build, see How to Pass a 3-Statement Modelling Test in 90 Minutes. For the single most common error candidates make under pressure, see Balance Sheet Not Balancing. For the accounting fundamentals interviewers drill before they ever let you near a model, see How to Answer Accounting Questions in IB Interviews.

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How to Build a 3-Statement Financial Model: Step-by-Step Guide