# DCF Sensitivity Analysis: WACC, Terminal Growth and Valuation Risk

> Build and interpret a reproducible DCF sensitivity table for WACC and terminal growth, with a five-year worked example and management decision rules.

- Canonical page: https://mtfinstitute.com/insights/dcf-sensitivity-analysis-wacc-terminal-growth-valuation-risk/
- Content type: Article
- Editorial category: Guides & Frameworks
- Publisher: MTF Institute of Management, Technology and Finance
- Author: MTF Institute Editorial Team- Published: 2026-08-11
- Updated: 2026-08-11
- Language: English
- Topics: Risk Management, Finance, Corporate Valuation, DCF

## DCF Sensitivity Analysis: WACC, Terminal Growth and Valuation Risk

A DCF sensitivity analysis shows how much a valuation changes when the weighted average cost of capital (WACC) and terminal growth rate change. Its purpose is not to find the most attractive cell in a spreadsheet. It is to reveal whether a decision is robust to reasonable uncertainty in the assumptions that dominate value.

This guide builds a reproducible five-year example, calculates a two-variable sensitivity matrix and turns the output into decision rules for managers and analysts.

## What the sensitivity table is testing

For a standard enterprise-value DCF, the model discounts forecast free cash flow to the firm (FCFF) and a terminal value:

`Enterprise value = Σ FCFF_t / (1 + WACC)^t + Terminal value / (1 + WACC)^n`

Using the perpetual-growth method at the end of forecast year `n`:

`Terminal value_n = FCFF_n × (1 + g) / (WACC - g)`

where `g` is the terminal growth rate. The formula requires `WACC > g`. That mathematical condition is necessary but not sufficient: the assumptions must also make economic sense for the business, currency, inflation basis and long-run market.

WACC and terminal growth affect the same valuation in opposite directions:

- a higher WACC reduces the present value of forecast and terminal cash flows;
- a higher terminal growth rate increases terminal value;
- a smaller gap between WACC and `g` makes the terminal-value formula highly sensitive.

This article uses WACC as an input. It does not teach how to construct the discount rate; that is a separate managerial and governance decision.

## Worked five-year DCF example

Assume a business is expected to generate the following FCFF, in EUR millions:

| Year | FCFF (EUR m) |
|---:|---:|
| 1 | 8.0 |
| 2 | 9.0 |
| 3 | 10.0 |
| 4 | 11.0 |
| 5 | 12.0 |

The base case uses:

- WACC: 10.0%;
- terminal growth: 3.0%;
- terminal value measured at the end of Year 5;
- all annual cash flows assumed to occur at period end;
- no mid-year convention, non-operating assets or enterprise-to-equity adjustments.

### Step 1: discount the explicit forecast

`PV of forecast FCFF = 8/1.10 + 9/1.10² + 10/1.10³ + 11/1.10⁴ + 12/1.10⁵`

The result is **EUR 37.19 million**.

### Step 2: calculate terminal value

`Terminal value at Year 5 = 12 × 1.03 / (0.10 - 0.03) = EUR 176.57 million`

### Step 3: discount terminal value

`PV of terminal value = 176.57 / 1.10⁵ = EUR 109.64 million`

### Step 4: calculate enterprise value

`Enterprise value = 37.19 + 109.64 = EUR 146.83 million`

The present value of the terminal value is **74.7%** of the enterprise value. That concentration is not automatically an error, but it tells management that assumptions beyond the explicit forecast drive most of the conclusion.

## The WACC–terminal-growth sensitivity matrix

Holding the five forecast cash flows constant, the following matrix recalculates enterprise value for five WACC values and five terminal growth rates. All figures are EUR millions.

| WACC \ Terminal growth | 1.0% | 2.0% | 3.0% | 4.0% | 5.0% |
|---:|---:|---:|---:|---:|---:|
| 8.0% | 157.2 | 178.2 | 207.6 | 251.7 | 325.2 |
| 9.0% | 136.7 | 151.9 | 172.1 | 200.5 | 243.0 |
| 10.0% | 120.8 | 132.2 | **146.8** | 166.3 | 193.7 |
| 11.0% | 108.1 | 116.9 | 127.9 | 142.0 | 160.8 |
| 12.0% | 97.8 | 104.7 | 113.2 | 123.8 | 137.4 |

The full grid ranges from EUR 97.8 million to EUR 325.2 million. That is not a probability interval. It is a map of model outputs conditional on the specified input combinations.

If management regards WACC of 9–11% and terminal growth of 2–4% as the central plausible range, the corresponding values span EUR 116.9 million to EUR 200.5 million. A proposed offer expressed on the same enterprise-value basis, or an investment threshold inside that interval, depends heavily on assumptions; an enterprise-value offer well above it demands a separate source of value or stronger evidence.

## How to interpret the table without cherry-picking

### 1. Define the plausible range before looking at the answer

If a team adjusts the input range after seeing the valuation, the analysis becomes a negotiation with the spreadsheet. Document the range, source date, currency and rationale before reviewing the matrix.

[Current valuation data published by Aswath Damodaran at NYU Stern](https://pages.stern.nyu.edu/~adamodar/New_Home_Page/datacurrent.html) include industry costs of capital, betas, capital structures and other reference measures. Such data can inform a benchmark, but they do not replace company-specific judgment about operating risk, financing and geography.

### 2. Read diagonally, not cell by cell

The bottom-left region combines a high discount rate with low terminal growth and produces lower values. The top-right combines a low discount rate with high terminal growth and produces higher values. The diagonal pattern exposes whether small joint changes move the decision materially.

### 3. Measure terminal-value dependence

The base case derives 74.7% of value from the discounted terminal value. Management should therefore challenge:

- whether Year 5 represents a stable operating state;
- whether margins and reinvestment can support the assumed growth;
- whether forecast FCFF and terminal growth are internally consistent;
- whether the discount rate and cash flows use consistent nominal or real terms;
- whether the forecast and terminal value double count an improvement.

### 4. Link the matrix to a decision threshold

A sensitivity table becomes useful when compared with a threshold:

- maximum acquisition price;
- minimum value required to approve an investment;
- carrying amount in an impairment review;
- financing capacity or covenant headroom;
- value per share after a separate enterprise-to-equity bridge.

Do not treat enterprise value as the amount available to shareholders. Debt, cash, leases, non-controlling interests and other adjustments require a separate bridge.

### 5. Add operating sensitivities

A WACC–growth matrix tests two valuation inputs while holding the operating forecast constant. It cannot answer what happens if revenue, margin, working capital, capital expenditure or implementation timing changes. Use a separate scenario analysis for those drivers, then run a valuation sensitivity table for each coherent scenario if the decision warrants it.

## Five decision rules for DCF sensitivity analysis

| Rule | Management question | Action |
|---|---|---|
| Reject invalid combinations | Is WACC less than or equal to terminal growth? | Remove the cell; do not report a meaningless result |
| Pre-commit the range | Were inputs selected before reviewing the value? | Record sources, date and rationale |
| Focus on decision stability | Does the recommendation change within a plausible central range? | Escalate assumption risk if it does |
| Expose terminal concentration | How much value comes from the terminal period? | Challenge steady-state economics and consider a longer explicit forecast |
| Separate model layers | Are operating scenarios, discount-rate sensitivity and EV-to-equity adjustments mixed together? | Analyse and reconcile them separately |

These rules prevent a common failure: presenting a wide grid while discussing only the preferred base case.

## Sensitivity analysis is not a probability model

A two-variable table says, “If WACC is X and terminal growth is Y, value is Z.” It does not say how likely X or Y is. Nor does it capture correlation: a difficult operating environment may simultaneously reduce cash flows, increase financing risk and lower sustainable growth.

For high-stakes decisions, complement the matrix with:

- downside, base and upside operating scenarios;
- break-even or switching-value analysis;
- evidence-weighted ranges for key assumptions;
- a decision tree for discrete events such as regulatory approval or product launch;
- a record of which assumptions management can influence.

The [HM Treasury Green Book 2026](https://www.gov.uk/government/publications/the-green-book-appraisal-and-evaluation-in-central-government/the-green-book-2026) is written for public-sector appraisal, not corporate WACC. Its emphasis on options, discounting, risk, uncertainty and clear communication of assumptions is nevertheless a useful methodological reminder: decision-makers need to see how uncertainty changes the preferred option.

## Accounting and valuation boundaries

[IAS 36 Impairment of Assets](https://www.ifrs.org/issued-standards/list-of-standards/ias-36-impairment-of-assets/) describes value in use as expected future cash flows discounted to present value using an appropriate discount rate. That is a specific accounting context; it does not make every transaction DCF an IAS 36 valuation.

Similarly, [IFRS 13](https://www.ifrs.org/issued-standards/list-of-standards/ifrs-13-fair-value-measurement/) defines fair value as an exit price under current market-participant assumptions. A management DCF based on company-specific plans may be an intrinsic decision model, not automatically an IFRS fair-value measurement. Clarify the valuation purpose before selecting assumptions or labels.

## A board-ready conclusion

A useful DCF sensitivity conclusion can be written in four sentences:

1. State the base enterprise value and the assumptions that produce it.
2. State the credible central range and why those inputs are credible.
3. Identify the variables and terminal-value dependence that threaten the recommendation.
4. State what evidence, price change or operating milestone would change the decision.

That turns a matrix from a spreadsheet exhibit into a management control.

For a broader sequence connecting financial analysis, capital budgeting, valuation and M&A, explore the [Executive Certificate in Strategic Finance, M&A & Corporate Valuation](https://mtfinstitute.com/lp/strategic-finance/).


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