Is the discount rate the same as WACC?

For valuing an entire company, yes — WACC is the standard discount rate, because it reflects the blended cost of all the capital that funds the business. Some analysts use a different rate when valuing only the equity, but for a whole-company DCF, WACC is the right choice.

What happens if I use the wrong discount rate?

A discount rate that's too low inflates the present value of future cash and makes companies look cheaper than they are; one that's too high does the opposite. Because terminal value is so sensitive to the rate, even small errors can produce large valuation mistakes.

What discount rate should I use for a DCF?

Use the company's estimated WACC. If you can't estimate it confidently, run the valuation across a range of plausible rates rather than betting on a single number.

How does the growth rate in terminal value relate to WACC?

The terminal value divides by (WACC − growth rate), so the two work against each other. The perpetual growth rate should always be modest — usually no higher than long-run economic growth — and well below the WACC, or the formula breaks down.

Why is my DCF so sensitive to WACC?

Because both the discounting of distant cash flows and the terminal value depend heavily on the rate. This sensitivity is normal and is exactly why testing a range of WACC values is essential rather than optional.

How to Use WACC as a Discount Rate in a DCF Valuation

WACC is the discount rate that turns a company's future cash into today's value. Here's how discounting and terminal value work, with a simple example.

Once you've estimated a company's <a href="/blog/what-is-wacc-complete-guide">WACC</a>, the obvious question is: what do I actually do with it? The answer is that WACC is the discount rate in a discounted cash flow (DCF) valuation — the rate that converts a company's future cash flows into what they're worth today. This article shows how that conversion works, why WACC is the right rate to use, and walks through a simplified example.

Why future cash is worth less than today's cash

A dollar you'll receive in five years is worth less than a dollar in your pocket now, because today's dollar can be invested and grow in the meantime. "Discounting" is the arithmetic that accounts for this: it shrinks future cash back to its present value. The further away the cash is, and the higher the discount rate, the more it shrinks. So the discount rate you choose has an enormous effect on the answer — which is exactly why getting WACC sensible matters.

Why the discount rate is WACC

A company's cash flows are claimed by everyone who funded it: both shareholders and lenders. So the right rate to discount those cash flows is the blended cost of all that funding — which is precisely what WACC is. Using WACC ensures you're discounting at the true cost of the capital that produced the cash. Discount at a rate that's too low and you'll overvalue the business; too high and you'll dismiss good companies as overpriced.

Discounting cash flows: a simple example

Suppose TechCo is expected to produce free cash flows of $5.0 billion in Year 1, $5.5 billion in Year 2, and $6.0 billion in Year 3, and we use the WACC of 8.8% we estimated earlier. (Figures are illustrative.) To find each year's present value, divide by (1 + WACC) raised to the number of years: Year 1 is 5.0 / (1.088)¹ = $4.60 billion, Year 2 is 5.5 / (1.088)² = $4.65 billion, and Year 3 is 6.0 / (1.088)³ = $4.66 billion. Notice that even though the raw cash flows grow each year, their present values are flatter — because cash further out is discounted harder. Add these three present values together and you have the value of the first three years of cash: about $13.9 billion.

Terminal value: the cash beyond the forecast

A company doesn't stop generating cash after three years, so a DCF adds a terminal value to capture everything beyond the explicit forecast. A common method assumes cash flows grow at a small, steady rate forever:

Terminal value = next year's cash flow / (WACC − growth rate)

If TechCo's Year 4 cash flow is $6.15 billion (the Year 3 figure grown 2.5%) and we assume 2.5% perpetual growth, terminal value = 6.15 / (0.088 − 0.025) = 6.15 / 0.063 ≈ $97.6 billion. That's a value as of Year 3, so it must itself be discounted back to today: 97.6 / (1.088)³ ≈ $75.8 billion. Add the discounted cash flows and the discounted terminal value, and you get an estimated enterprise value of roughly $89.7 billion. Compare that to the company's actual market value and you have a view on whether it looks cheap or expensive — the foundation of <a href="/blog/how-to-find-undervalued-stocks">finding undervalued stocks</a>.

Why small WACC changes matter so much

Look again at the terminal value formula. The denominator is WACC minus the growth rate — a small number. If WACC were 8.3% instead of 8.8%, that denominator shrinks from 0.063 to 0.058, and the terminal value jumps by roughly 9%. A half-point change in WACC can swing a valuation dramatically. This is the single most important lesson of DCF work: always test a range. Run your valuation at a WACC a point higher and a point lower, and treat the spread — not a single figure — as your real answer. The <a href="/financial-tools/wacc-calculator">WACC calculator</a> makes this easy: change one input and immediately see the new rate, then re-run your discounting with it.

Open WACC Calculator

A quick checklist for using WACC in a DCF

Putting it together, the process runs in five steps. First, estimate the company's WACC — its cost of equity and after-tax cost of debt, blended by funding weights. Second, forecast free cash flows for a sensible window, often five to ten years. Third, discount each year's cash flow back to today using the WACC. Fourth, estimate a terminal value for the cash beyond the forecast, and discount that back too. Fifth, add it all up for an enterprise value — then test how much it moves when WACC changes. If any of these steps feel unfamiliar, start with the <a href="/blog/what-is-wacc-complete-guide">WACC cornerstone guide</a> and the <a href="/learn/investing-for-beginners">investing for beginners hub</a>, then come back and put the numbers to work.