· Kai · 7 min read · Technicals
Interviewers seldom ask "what is NOPAT?" on its own. It turns up inside other questions: the first step of a DCF, a discussion of return on capital, a case comparing two companies with different balance sheets. If you can explain why the tax charge sits on EBIT and not on pre-tax income, you can handle all of them.
The NOPAT formula
The formula fits on one line:
NOPAT = EBIT × (1 - tax rate)
EBIT is operating income: revenue minus operating costs, including depreciation and amortisation, before interest and tax. You apply the tax rate to EBIT itself, before any interest comes off. If the line between EBIT, EBITDA and net income still feels shaky, EBIT vs EBITDA vs Net Income sets them side by side.
Some analysts use NOPLAT for a version with extra adjustments. In an interview, treat NOPLAT, EBIAT and tax-effected EBIT as NOPAT unless asked to separate them.
Why NOPAT ignores debt
A company with debt pays less tax than an identical company without it, because interest is deductible: its taxable income is EBIT minus interest. NOPAT skips that step on purpose. It charges a hypothetical tax on the whole of EBIT, as though the interest did not exist.
An interviewer wants to hear two reasons for that.
The first is comparability. NOPAT measures what the operations earn for everyone who funded them, lenders and shareholders together. Two businesses with the same operations and different borrowing will report different net income and the same NOPAT, which lets you judge the operations apart from the financing decision.
The second is avoiding a double count. You already capture the tax benefit of debt in the discount rate, because WACC uses the after-tax cost of debt. Aswath Damodaran sets this out in his NYU Stern paper on measuring return on capital: if you plug in the taxes a company paid, you count the interest tax saving once in the return and a second time in the cost of capital.
An illustrative example with round numbers
Take two companies with identical operations: EBIT of 200 and a tax rate of 25%. Company A has no debt. Company B pays 40 of interest a year.
| Line item | Company A | Company B |
|---|---|---|
| EBIT | 200 | 200 |
| Interest | 0 | 40 |
| Pre-tax income | 200 | 160 |
| Tax at 25% | 50 | 40 |
| Net income | 150 | 120 |
| NOPAT (EBIT × 0.75) | 150 | 150 |
Illustrative figures, invented to show the mechanics.
Both companies have NOPAT of 150, even though B's net income is 30 lower. B's tax bill is 10 lower than A's, and that 10 is the interest tax shield: 40 of interest multiplied by the 25% rate, and NOPAT leaves it out.
You can also work up from net income by adding back interest after tax. For Company A, with no debt and no non-operating items, NOPAT and net income are the same number. For Company B, the add-back closes the gap:
120
Net income
30
Interest after tax (40 × 0.75)
Illustrative figures from the example above: the same 150 you reach by taxing EBIT.
NOPAT in a DCF, ROIC and EVA
Unlevered free cash flow
In a DCF, NOPAT is the first line of unlevered free cash flow:
Unlevered FCF = NOPAT + D&A - capex - increase in net working capital
That is the "start from EBIT, tax it" step in the four-step DCF walkthrough. Because NOPAT excludes interest, the cash flow belongs to debt and equity holders together, so you discount it at WACC to reach enterprise value.
Return on invested capital
ROIC divides NOPAT by the capital tied up in the business: debt plus equity, net of cash. Damodaran's paper defines it using book values, with invested capital taken from the start of the year. You then set ROIC against WACC. A business that earns more on its capital than the capital costs adds value as it grows; one that earns less loses value the more it reinvests.
Economic value added
EVA turns that comparison into an amount of money:
EVA = NOPAT - (WACC × invested capital)
Rearranged, that is (ROIC minus WACC) multiplied by invested capital. A positive figure means the business earned more than its lenders and shareholders required. Damodaran publishes EVA by US sector, setting each industry's return on capital against its cost of capital.
The judgement calls behind the formula
The arithmetic is mechanical. The inputs involve choices, and a good interviewer will push on them.
- The tax rate. Damodaran's definition allows either an effective or a marginal rate. The rule that matters is applying your chosen rate to operating income, since the taxes a company paid already include its interest deduction. In a model, state which rate you used and why.
- One-off items. Restructuring charges, impairments and gains on asset sales can distort a single year's EBIT. Decide whether to strip them out, apply the same rule to every company you compare, and read the footnotes before accepting a company's own adjusted figure.
One input is not a judgement call at all:
How to say it in an interview
"NOPAT is net operating profit after tax: EBIT multiplied by one minus the tax rate. It shows what the operations earn after tax as if the company had no debt, so it belongs to lenders and shareholders together and lets you compare companies with different capital structures. It is the starting point for unlevered free cash flow in a DCF and the numerator in return on invested capital."
That takes about half a minute. Then stop, and have these follow-ups ready.
"Why not use the taxes the company paid?" Those taxes already reflect the interest deduction. Counting that saving in NOPAT, and again through the after-tax cost of debt in WACC, would double count it.
"The company borrows more. What happens to NOPAT?" Nothing, provided the operations are unchanged. Interest rises, the tax bill falls, net income falls, and NOPAT stays where it was.
"Can net income ever be higher than NOPAT?" Yes. A company with a large cash balance and little debt can earn more interest than it pays. That net interest income lifts net income but sits outside NOPAT. A non-operating gain, such as a profit on selling an investment, has the same effect.
How to make it stick this week
- Rebuild the two-company example from memory with your own numbers, and check that NOPAT comes out the same both ways: down from EBIT and up from net income.
- Say the half-minute answer out loud until you can give it without notes, then have someone ask you the three follow-ups in random order.
- Calculate NOPAT and ROIC for one real company from its annual report. Pick your tax rate, write down why, and compare the result with its sector on Damodaran's tables.
The same matching rule, pre-interest figures paired with enterprise value, also governs valuation multiples. More free material is in the Knowledge Base, and new pieces land in IBB Insights.
Reading about it is step one.
Practice is step two — members drill these questions in the Superday Dojo, graded on whether they understood the concept. The Knowledge Base has more to read in the meantime.