DCF Valuation: A Founders Guide to Discounted Cash Flow

A discounted cash flow (DCF) valuation estimates what a business is worth today by projecting the cash it will generate in future years and then shrinking each of those future amounts back to a present value. The logic is simple: money you get later is worth less than money you get now, so you discount it. Add up all those discounted cash flows, including one big figure for everything past the forecast window, and you have the business value. It is the method investors and acquirers reach for when they want a number built from first principles rather than a rule of thumb, and it is one of the core approaches in our wider guide on how to value a business.

Ask a founder what the company is worth and you will usually hear a multiple of last year’s profit. Ask the person writing the check, and behind their offer is almost always a DCF. Learn how it works and you stop being surprised by the numbers other people put on your company. You start seeing where those numbers come from, and where you can push back.

Why money tomorrow is worth less than money today

The whole engine runs on one idea. A dollar you will receive in five years is worth less than a dollar in your hand right now. Two reasons. Time: a dollar today can be put to work and grow, so waiting has a cost. Risk: the future dollar might never show up if the business stumbles. A DCF prices both by shrinking each future cash flow back to what it is worth today. The riskier and more distant the cash, the harder the discount bites. Cash five years out gets cut far more than cash next year, and cash from a fragile business gets cut more than cash from a steady one.

The DCF formula, decoded

Written out, it looks worse than it is:

Value = FCF₁/(1+r)¹ + FCF₂/(1+r)² + … + FCFₙ/(1+r)ⁿ + Terminal Value/(1+r)ⁿ

• FCFₜ = the free cash flow the business generates in each future year
• r = the discount rate (the risk-and-time cost, usually the WACC)
• n = the number of forecast years, typically five
• Terminal Value = everything the business earns beyond the forecast, captured in one figure

That is the entire method. The rest is just filling in three inputs: the cash flows, the rate, and the terminal value. Make those three defensible and you have a valuation you can argue for in a room full of people trying to move it.

Step 1: Forecast free cash flow (what “free” actually means)

Free cash flow is the cash left over after the business pays to keep itself running and growing. It is the money genuinely available to the people who funded it. You build it like this: take operating profit, tax it, add back non-cash charges like depreciation, then subtract what you plow back into equipment (capex) and into working capital. Written as a formula, FCF = EBIT × (1 – tax) + depreciation – capex – change in working capital.

Here is where founders fool themselves. They treat EBITDA as cash. It is not. A company can post healthy EBITDA and still bleed cash all year if it is stocking inventory, funding customers who pay in ninety days, or replacing machinery that wore out. A DCF forces the honest question: after everything the business actually needs to keep going, what is left? Forecast that number for five years off your real drivers – orders, pricing, headcount, collection cycles – not a tidy line sloping up and to the right. The forecast is where you either tell the truth about the business or quietly flatter it, and a buyer’s analyst will find the flattery.

Step 2: Pick the discount rate (WACC without the pain)

The discount rate is the risk dial on the whole model. It is usually the weighted average cost of capital (WACC), a blend of the return equity investors expect and the after-tax cost of any debt. Turn the dial up and the value drops. Turn it down and the value climbs. Nothing else in the model moves the answer this quietly or this much.

Here is what the textbook examples skip. They run a listed company at 8 to 10 percent. A private company deserves far more, often 12 to 18 percent, and higher for genuinely risky ones, once you stack on the premiums a private business earns: it is smaller, its shares cannot be sold quickly, and it leans on a handful of key people. A useful way to see it is base cost of capital plus a size premium plus an illiquidity premium. For micro-cap firms the size premium alone can add several points to the cost of equity. This one input is the silent killer of valuations. Two extra points on the rate can knock a fifth off the answer, which is exactly why the discount rate is where deals get quietly won and lost while everyone argues about revenue growth.

Step 3: Terminal value, the number that decides everything

A five-year forecast ignores year six and every year after it, which for most companies is where the majority of the worth actually sits. The terminal value captures all of it in one figure. Two common ways to build it. The Gordon growth method assumes cash flows grow forever at a modest rate: TV = final-year FCF × (1 + g) / (WACC – g). The exit multiple method applies a realistic sale multiple to the final year’s EBITDA. One firm rule holds either way: the perpetual growth rate g must not exceed long-run economic growth, which sits around 2 to 3 percent in most economies. Break that rule and you are quietly claiming your company eventually swallows the entire economy, and any serious reviewer throws the model out. Because this single figure carries so much weight, getting it right matters more than fine-tuning the near-term cash flows.

A worked example: valuing a $10M-revenue company end to end

Take a profitable $10M-revenue business. Forecast five years of free cash flow, use a 15% WACC, and assume 4% terminal growth. All figures in $ millions:

Look at what just happened. The terminal value is $11.28M of a $16.5M answer, roughly 68 percent of the whole valuation. A “five-year DCF” is mostly a bet on year six to forever. Terminal value running 60 to 80 percent of the total is normal, not a sign you did something wrong, which is exactly why that one figure deserves the most scrutiny. Cross-check it with the exit multiple to stay honest: year-five EBITDA of about $3.0M at an 8x multiple gives a $24M terminal value and an enterprise value near $17.2M, close enough to trust the range. One last move in practice: subtract net debt from enterprise value and you get equity value, what the shares are actually worth to their owners.

How minor assumption changes swing the valuation

Change nothing about the business. Change only the assumptions. Watch the value move:

Two points on the discount rate, in either direction, and the number lurches by a fifth or more. That is why a serious valuation is a range with a sensitivity table, not a single number. Anyone who hands you one precise DCF figure without showing how it moves is selling a precision they do not have. The deliverable that matters is the list of assumptions and how much each one bends the answer. That is the document you actually negotiate from.

When DCF fails: startups and pre-revenue companies

For an early-stage startup a DCF is not just harder, it is structurally unreliable. There is no operating history to forecast from. Near-term free cash flow is usually negative. And there is no defensible discount rate for a two-founder company, where the real cost of risk can run 30 to 60 percent a year. Stack those together and the terminal value becomes nearly the entire answer, so the “valuation” is one large guess about a distant future dressed up as math. Push the discount rate high enough and the model can even spit out a negative number. That is precisely why investors price early rounds off comparable deals and methods built for uncertainty – the venture-capital method, the scorecard method, the Berkus method – rather than a DCF. If that is your stage, read how startups are actually valued instead.

What founders should take away

A DCF is not spreadsheet theater. It is negotiation logic. Its value to you is not the point estimate, it is knowing which single assumption the other side’s number hangs on – usually the terminal growth rate, the discount rate, or the margin ramp – so you can defend your view of it line by line. When the number carries real money, the assumptions and the range are what protect you. That is where an experienced pair of hands earns its keep.

Heading into a raise, a sale, or a shareholder conversation and want a valuation that holds up when someone pushes back? KayOne builds the model on your real numbers and stays on the hook for it. See our business valuation services, or see if we’re a fit.