Terminal Value Sensitivity Explained: A Step-by-Step Numerical Example

In most DCFs, the terminal value is the single biggest driver of the valuation. Small tweaks to the discount rate or the long-term growth rate can swing your answer by hundreds of millions of dollars.

That's why interviewers love asking about it. In this post, we'll build a simple DCF from scratch, run a full sensitivity table, and break down why the numbers move the way they do. By the end, you'll be able to explain terminal value sensitivity with real numbers, not hand-waving.

Why Terminal Value Sensitivity Matters

A DCF has two parts:

• The explicit forecast period: usually 5 to 10 years of projected free cash flows
• The terminal value (TV): everything the business is worth after that period, rolled into one number

Because the terminal value captures all the years after the forecast, it often makes up 60% to 80% or more of total enterprise value. So if your TV assumptions are shaky, your whole valuation is shaky.

The two assumptions that drive it under the perpetuity growth method:

• WACC (discount rate)
• Terminal growth rate (g)

Let's see how much they matter.

Step 1: Set Up the Base Case

Imagine a company with these projected unlevered free cash flows (in $ millions):

Base case assumptions:

• WACC: 10%
• Terminal growth rate: 2.5%
• End-of-year discounting (no mid-year convention, to keep it clean)

Discount the forecast cash flows

Each cash flow gets divided by (1 + WACC) raised to the year number:

So the five forecast years are worth about $447.7 million today.

Calculate the terminal value

Using the Gordon Growth formula:

TV = FCF Year 5 × (1 + g) / (WACC − g)

TV = 140 × 1.025 / (0.10 − 0.025) TV = 143.5 / 0.075 TV = $1,913.3 million

That's the value at the end of Year 5. You still need to bring it back to today:

PV of TV = 1,913.3 / 1.6105 = $1,188.0 million

Add it up

Notice that about 73% of the valuation comes from the terminal value. That's very normal, and it's exactly why sensitivity analysis is so important.

Step 2: Build the Sensitivity Table

Now let's flex WACC between 9% and 11%, and terminal growth between 2.0% and 3.0%. Every cell below is a full recalculation of enterprise value.

Enterprise value ($ millions):

Look at the corners:

• Lowest value: 1,377 (11% WACC, 2.0% growth), about 16% below the base case
• Highest value: 2,022 (9% WACC, 3.0% growth), about 24% above the base case

So a "reasonable" one-point range in WACC and half-point range in growth gives you a valuation spanning roughly $1.4 billion to $2.0 billion. Same company, same cash flow forecast.

Step 3: Understand Why the Numbers Move

Memorizing the table won't help you in an interview. Understanding the mechanics will.

The spread is everything

The heart of the terminal value formula is 1 / (WACC − g). Think of it as a multiplier applied to next year's cash flow:

Going from a 7.5% spread to a 6.0% spread raises the multiplier by 25%. That's a huge jump from what sounds like small assumption changes.

Sensitivity is not symmetric

Notice that the upside (+24%) is bigger than the downside (−16%). That's because the formula divides by the spread. As the spread shrinks, each additional cut in it has a bigger and bigger effect.

You can see it directly in the table. Raising growth from 2.5% to 3.0% adds:

• $127 million when WACC is 9%
• $91 million when WACC is 10%
• $68 million when WACC is 11%

The lower the discount rate, the more sensitive the valuation becomes to growth. This is also why plugging in a terminal growth rate close to WACC produces absurd numbers. If WACC and g were equal, the formula would blow up entirely.

WACC hits twice

WACC affects your valuation in two places:

1. It sets the denominator of the terminal value formula
2. It discounts everything back to today, including the TV itself

Terminal growth only affects the first. That's one reason a 1-point change in WACC usually moves the valuation more than a 0.5-point change in growth.

The TV share moves too

The heavier the terminal value, the more fragile the valuation:

• At 9% WACC / 3.0% growth, TV is about 77% of enterprise value
• At 11% WACC / 2.0% growth, TV is about 68% of enterprise value

When the assumptions get more optimistic, more of your answer depends on the distant future.

Step 4: See What Happens to the Share Price

Here's a point many candidates miss: sensitivity gets amplified at the equity level when the company has debt.

Let's say the company has $600 million of net debt and 100 million shares.

Enterprise value moved −16% / +24%. The share price moved −25% / +37%.

Why? Net debt is a fixed number subtracted from a moving EV. Every dollar of EV change lands entirely on equity, which is a smaller base. Same logic as financial leverage on returns.

Step 5: Sanity-Check the Terminal Value

A good banker doesn't just trust the perpetuity growth output. They cross-check it.

Check the implied exit multiple. Suppose Year 5 EBITDA is $200 million. The base case TV of $1,913 million implies:

1,913 / 200 = about 9.6x EV/EBITDA

Then ask: is that in line with where comparable companies trade? If peers trade at 7x, your growth assumption might be too generous. If they trade at 14x, it might be too conservative.

Other quick checks:

• Is g below long-run nominal GDP growth? A company can't outgrow the economy forever, so terminal growth is usually set in the low single digits.
• Is the Year 5 cash flow "normalized"? If Year 5 includes a one-off spike or a huge capex dip, your TV will be distorted, since you're growing that number into perpetuity.
• Does reinvestment support the growth? Growth isn't free. A business growing forever needs to keep investing, and the terminal FCF should reflect that.

How This Shows Up in Interviews

Here are questions you should be ready for, plus the core of a strong answer.

"Which matters more, WACC or terminal growth?"

Generally, a 1% change in WACC has a bigger impact than a 1% change in growth, because WACC affects both the TV formula and the discounting of every cash flow. But both act through the same spread, so the lower that spread, the more sensitive everything gets.

"Why is the terminal value such a big percentage of EV?"

Because it represents every year after the forecast period. For a stable, growing company, years 6 to infinity contain far more total cash flow than years 1 to 5, even after discounting.

"How would you reduce the dependence on terminal value?"

A few options:

• Extend the forecast period so more value sits in explicit, modeled years
• Cross-check with the exit multiple method
• Present a sensitivity table rather than a single point estimate

"Walk me through what happens if growth rises from 2.5% to 3%."

Use the numbers: at a 10% WACC, the spread falls from 7.5% to 7.0%, the TV goes from about $1,913 million to $2,060 million, and enterprise value rises from about $1,636 million to $1,727 million, roughly a 6% increase.

Excel Tip: Build It With a Data Table

On the job (and in modeling tests), you'll build this with Excel's Data Table feature:

1. Put your WACC values down a column and your growth rates across a row
2. Link the top-left corner cell to your enterprise value (or share price) output
3. Select the whole grid, go to Data → What-If Analysis → Data Table
4. Set the row input cell to your growth assumption and the column input cell to your WACC assumption

One heads-up: data tables recalculate constantly and can slow down large models. Many bankers set Excel to "Automatic except for data tables" while building.

The Bottom Line

Terminal value sensitivity comes down to one idea: the valuation lives and dies by the spread between WACC and terminal growth.

In our example, modest assumption changes moved enterprise value from about $1.4 billion to $2.0 billion and the share price from under $8 to over $14. Once you can rebuild that logic on a whiteboard and explain why it's asymmetric, you'll handle any DCF sensitivity question an interviewer throws at you.

Practice running these numbers yourself with a different set of cash flows. Doing the math once by hand is the fastest way to make it stick.