What a business is worth, based on the cash it will produce
Discounted cash flow, or DCF, is the most fundamental way to value a company. The idea behind it is intuitive: a business is worth the cash it will generate for its owners over its lifetime, adjusted for the fact that money in the future is worth less than money today. Everything else — price-to-earnings ratios, rules of thumb, comparisons to peers — is ultimately a shortcut for this single principle.
Would you rather have $100 today or $100 in five years? Obviously today, because you could invest it, and because the future is uncertain. That simple preference is the heart of DCF. A dollar expected next year is worth slightly less than a dollar in hand; a dollar expected in ten years is worth much less. To compare cash flows arriving at different times, we “discount” each future dollar back to its value today using a discount rate. The further out the cash, and the higher the rate, the more it shrinks.
The cash flows that matter in a DCF are free cash flows — the cash left after the company pays its operating costs and the capital expenditures needed to keep growing. You estimate these for a forecast period, typically five to ten years, based on assumptions about revenue growth, profit margins, and reinvestment needs. This is where most of the judgment lives: your view of how fast the company grows and how profitable it stays drives the entire result.
The discount rate reflects the return investors require to hold the asset, given its risk. For a whole company, analysts often use the weighted average cost of capital (WACC), which blends the cost of equity and the after-tax cost of debt. A riskier, more volatile business demands a higher discount rate; a stable, predictable one can use a lower rate. Small changes here move the valuation a lot, which is why the discount rate is one of the most scrutinized inputs in any model.
A company does not stop producing cash at the end of your forecast window, so you need to capture everything beyond it. This is the terminal value, and for most companies it represents the majority of the total valuation. Two common methods are the perpetuity-growth approach (assume free cash flow grows forever at a modest, sustainable rate — usually no higher than long-run economic growth) and the exit-multiple approach (apply a reasonable valuation multiple to the final year's cash flow or earnings). Because the terminal value is so large, conservative assumptions here are essential.
With projected free cash flows and a terminal value in hand, you discount each one back to the present using the discount rate, then add them up. The result is the estimated enterprise value. Subtract net debt and you arrive at the equity value; divide by shares outstanding and you get an estimated intrinsic value per share. Compare that to the current market price: if the intrinsic value is meaningfully higher, the stock may be undervalued by your assumptions; if lower, it may be expensive.
A DCF is only as good as its inputs, and small tweaks to growth rates, margins, or the discount rate can swing the output dramatically. This is a feature, not a bug — it forces you to be explicit about what you believe. The most useful way to run a DCF is not to chase one “true” number but to test a range: pessimistic, base, and optimistic cases. If a stock looks attractive even under conservative assumptions, that is a far stronger signal than a single rosy estimate. Treat the output as a disciplined opinion, never a fact.
Building a DCF by hand is educational but time-consuming. QuantStrike generates a discounted-cash-flow model for thousands of companies automatically, with the assumptions laid out so you can see exactly what drives the value — then pair it with the QS Score and the full analysis framework for a complete picture.
Disclaimer: This article is for informational and educational purposes only and is not financial advice or a recommendation to buy or sell any security. Valuation models rely on assumptions that may prove incorrect. Always do your own research.