What Is a DCF Model?
A Discounted Cash Flow model answers a single question: "What is a stream of future cash flows worth in today's dollars?"
The logic is simple. A dollar today is worth more than a dollar next year, because you could invest today's dollar and earn a return. So future cash flows need to be "discounted" back to the present to reflect this time value of money.
A DCF model for a stock works like this:
- Estimate how much free cash flow the company will generate each year for the next 10 years
- Estimate what the company will be worth at the end of those 10 years (terminal value)
- Discount all of those future values back to today using an appropriate interest rate
- Sum everything up and divide by shares outstanding
The result is your estimate of the stock's intrinsic value per share.
Step 1: Get Free Cash Flow from SEC Filings
Free cash flow = Operating Cash Flow - Capital Expenditures.
Both numbers are on the company's Cash Flow Statement, which is filed with the SEC in the 10-K (annual) and 10-Q (quarterly) reports. On FairValueLabs, we pull this data directly from the SEC EDGAR XBRL API.
You want at least 5 years of history (we use 10) to calculate a reliable growth trend. Here's what you're looking for:
- Operating Cash Flow: the cash generated from the company's core business operations
- Capital Expenditures (CapEx): cash spent on maintaining or expanding property, plant, and equipment
- Free Cash Flow (FCF): the difference — this is what's actually available to return to shareholders via dividends, buybacks, or debt reduction
A company with consistently positive and growing FCF is a much more reliable DCF candidate than one with volatile or negative FCF.
Step 2: Project Future Growth
This is where the art meets the science. You need to estimate how fast free cash flow will grow over the next 10 years.
Our approach: We calculate the Compound Annual Growth Rate (CAGR) of FCF over the past 10 years and use that as the base projection. We cap growth at 15% to avoid over-optimistic projections, and we floor it at -5% to handle companies in temporary decline.
The two-stage model: Many companies grow faster in the near term and slower in the long term. A two-stage DCF projects higher growth for years 1-5 and a reduced growth rate for years 6-10. This is more realistic for growth companies.
The growth rate is the single most impactful assumption in the model. A change from 8% to 12% growth can increase the intrinsic value by 40% or more.
Step 3: Calculate the Discount Rate (WACC)
The Weighted Average Cost of Capital (WACC) is the rate at which you discount future cash flows back to today. It reflects:
- Cost of equity: what return shareholders require (we estimate using the Capital Asset Pricing Model — risk-free rate + beta * equity risk premium)
- Cost of debt: the after-tax interest rate the company pays on its debt
- Capital structure: the ratio of equity to debt in the company's financing
For a typical US large-cap company, WACC falls between 8-12%. Higher risk companies (high beta, leveraged balance sheets) have higher WACC, which reduces the present value of their future cash flows.
On FairValueLabs, we calculate WACC from each company's actual capital structure and market data rather than using a one-size-fits-all rate.
Step 4: Estimate Terminal Value
You can't project cash flows to infinity — at some point, you need to cap the projection and estimate what the company will be worth beyond the projection period.
The most common approach is the Gordon Growth Model (perpetuity growth):
Terminal Value = FCF in Year 10 × (1 + g) / (WACC - g)
Where g is the perpetual growth rate — typically 2-3%, roughly matching long-term GDP growth. The assumption is that after your explicit projection period, the company grows at a modest, sustainable rate forever.
The terminal value often represents 60-80% of the total DCF value. This is why the perpetual growth rate matters so much — even small changes (2% vs. 3%) can swing the result significantly.
Step 5: Sum and Divide
Add up:
- The present value of each year's projected free cash flow (years 1-10)
- The present value of the terminal value (discounted back from year 10)
This gives you the enterprise value — the total value of the business. To get the equity value per share:
- Add cash and cash equivalents (on the balance sheet)
- Subtract total debt
- Divide by shares outstanding
The result is your estimated intrinsic value per share. Compare it to the current market price to determine the margin of safety.
Sensitivity Analysis: What Changes the Answer?
A single-point DCF estimate gives false precision. Run the model across a range of assumptions:
- Growth rate: What if growth is 2% lower or higher than your base case?
- WACC: What if the discount rate is 1% higher (more risk) or lower (less risk)?
- Terminal growth: What if the company grows at 1.5% vs. 3% in perpetuity?
Create a matrix showing intrinsic value at each combination. If the stock looks cheap across most scenarios, the investment case is strong. If it only looks cheap under the most optimistic assumptions, the case is weak.
On each FairValueLabs ticker page, we include a sensitivity table so you can see how the fair value estimate changes with different growth and discount rate assumptions.
How FairValueLabs Does It
Our automated DCF pipeline for every stock:
- Pulls 10 years of FCF data from SEC EDGAR XBRL API
- Calculates historical CAGR with growth rate capping (max 15%, min -5%)
- Projects two-stage cash flows (5 years at historical rate, 5 years at 50% of historical rate)
- Estimates terminal value at 2.5% perpetual growth
- Calculates WACC from each company's actual capital structure
- Discounts and sums to get per-share intrinsic value
- Compares to current market price for margin of safety
All inputs are sourced from public SEC filings. No analyst estimates, no proprietary data — everything is transparent and verifiable. You can see the complete breakdown on every ticker analysis page.