10.2 Building the Income Statement

Building a Driver-Based Income Statement

The income statement in a three-statement model is not a list of independently guessed dollars. It is a driver-based calculation: you set a small number of assumptions, and every P&L line is a formula. CFI's standard walk is:

Revenue → COGS → Gross profit → SG&A → D&A → EBIT → Interest → EBT → Tax → Net income

Some models fold D&A into SG&A on the face of the P&L and show it separately only in the notes and on the cash flow statement. Either presentation is fine if D&A is still sourced from the PP&E schedule, not from a free percent of revenue, and if the same D&A number is added back in CFO.

The drivers that belong on an assumptions tab, or in a clearly marked blue-input row, are:

Do not circularly pick NI as a percent of revenue while also independently forecasting everything above it. Year 0 Clearwater NI is $108,000 on $1,000,000 of sales, a 10.8% net margin. If you force Year 1 NI = 10.8% × $1,100,000 = $118,800 and you also forecast COGS 58%, SG&A 22%, D&A $42,000, interest $16,000, and tax at 25%, you have two different net incomes. The residual NI is $121,500. The forced-margin NI is $118,800. The $2,700 gap has nowhere honest to go: you will break RE, plug the gap into a mystery "other expense," or the balance sheet will not balance. Net margin is an output. You may use it as a sense-check (is 11.0% plausible versus 10.8% history?) but you do not type it as a forecast input when the lines above NI are already determined.

The Model Inverts at the Last Historical Year

Clearwater Tools has one historical year (Year 0) and two forecast years (Year 1 and Year 2). In the workbook, Year 0 income-statement dollars are hardcoded from the financials. Formulas compute the drivers:

• Revenue growth is not computed in Year 0 (this stub has no Year −1); it becomes an input starting in Year 1.
• COGS % = 580,000 / 1,000,000 = 58.0%
• SG&A excluding D&A % = 220,000 / 1,000,000 = 22.0%
• D&A = $40,000 from the PP&E schedule, which happens to be 4.0% of sales in Year 0 — a coincidence, not a driver.
• Interest = $16,000 (beginning debt $200,000 × 8%)
• Effective tax rate = 36,000 / 144,000 = 25.0%
• Net margin (output, not a driver) = 108,000 / 1,000,000 = 10.8%

Forecast years invert: you hardcode 10% then 8% revenue growth, hold COGS at 58% and SG&A at 22%, pull D&A from the schedule ($42,000 then $45,000), pull interest from the debt schedule ($16,000 then $14,400), and hold tax at 25%. The statements compute. Copying Year 0's $580,000 of COGS into Year 1 is the invert failure: you treated a forecast year as if it were historical.

Worked Three-Year Income-Statement Stub

Revenue path: Year 0 $1,000,000 (hardcoded). Year 1 = 1,000,000 × 1.10 = $1,100,000. Year 2 = 1,100,000 × 1.08 = $1,188,000.

COGS = 58% of revenue. Year 0 $580,000 (hardcoded, which implies 58%). Year 1 = 0.58 × 1,100,000 = $638,000. Year 2 = 0.58 × 1,188,000 = $689,040.

SG&A excluding D&A = 22% of revenue. Year 0 $220,000. Year 1 = $242,000. Year 2 = $261,360.

D&A from the PP&E schedule in section 10.3: Year 0 $40,000, Year 1 $42,000, Year 2 $45,000. Do not replace these with 4.0% of sales. That shortcut would put Year 1 D&A at $44,000 and immediately desync the P&L from PP&E and from the CFS add-back. D&A is a function of the asset base, useful lives, and capex timing, not of this year's revenue.

Interest from the debt schedule: beginning Year 1 debt $200,000 × 8% = $16,000. After a $20,000 Year 1 repayment, beginning Year 2 debt $180,000 × 8% = $14,400. Using beginning-of-year principal avoids circularity (interest depends on debt; cash depends on interest via NI; a revolver would make debt depend on cash). Minimum-cash and revolver circularity is Chapter 11. This chapter uses beginning debt so the income statement can close without iteration.

Tax = 25% × EBT. There is no tax on a percent of revenue. Interest tax-shields EBT, so a firm with more debt has a lower tax dollar even at the same EBIT. Year 1 tax of $40,500 is 3.7% of sales and 22.8% of EBIT — neither percentage is a driver.

Year 1 arithmetic

• Gross profit = 1,100,000 − 638,000 = $462,000
• EBIT = 462,000 − 242,000 − 42,000 = $178,000
• EBT = 178,000 − 16,000 = $162,000
• Tax = 0.25 × 162,000 = $40,500
• NI = 162,000 − 40,500 = $121,500

Net margin rose from 10.8% to 11.0% without any extra "margin improvement" lever. Revenue grew, COGS% and SG&A% were held flat, D&A rose only $2,000 (less than 10% of the revenue increase), and interest was unchanged in Year 1 because the repayment is modeled at year-end. Operating leverage plus a lagging interest line is enough to lift net margin. Year 2 lifts it again because interest falls to $14,400 after the Year 1 principal paydown. If you had locked NI at 10.8% of sales, you would have erased that real, mechanical improvement and booked $118,800 instead of $121,500.

EBITDA is not on the face of this P&L, but it is a useful cross-check: Year 1 EBITDA = EBIT $178,000 + D&A $42,000 = $220,000. That $220,000 is still not cash. Section 10.3 will show Year 1 CFO of $151,500 after ΔNWC, and cash after capex, debt paydown, and dividends rising only $35,050.

Order of Operations

CFI's guide to projecting balance-sheet line items gives the practical sequence, because D&A and interest are not free P&L inputs:

1. Project the income statement down to, but not including, D&A and interest (revenue, COGS, SG&A excluding D&A).
2. Project the balance-sheet working-capital accounts and the PP&E and debt schedules, which produce D&A and interest.
3. Finish the income statement: D&A, interest, tax, NI.
4. Finish the balance sheet: retained earnings (needs NI) and cash (needs the cash flow statement).

You will feel this order in Excel. You cannot type Year 1 D&A on the P&L until the PP&E schedule exists. You cannot type Year 1 interest until the opening debt balance is known. You cannot close RE until NI is known. You cannot close cash until CFO, CFI, and CFF are known. That is not a formatting preference. It is the dependency graph of an articulated model.

Exam Traps on the Income Statement Build

• D&A as a percent of sales. History may look like 4.0% ($40,000 / $1,000,000). Using 4.0% in Year 1 gives $44,000, not the schedule's $42,000. The BS and CFS then disagree with the P&L.
• Interest as a percent of sales. Interest is a function of debt and the coupon, not of revenue. Clearwater's sales rise 10% in Year 1; interest does not.
• Tax as a percent of sales or of EBIT. Tax is on EBT. Interest tax-shields the tax line.
• Hardcoding forecast dollars that should be drivers. If the case changes growth from 10% to 12% and your COGS does not move, you hardcoded the wrong thing.
• Forcing NI or EBITDA as a percent of revenue in addition to the line-item drivers. One residual, not two.
• Mixing historical hardcodes into forecast formulas by copying Year 0 dollars across instead of copying Year 0 percents.

The income statement is now a residual machine that will feed RE and CFO. Section 10.3 builds the stocks and the cash reconciling statement that make the residual land on a balanced sheet.