Free Discounted Cash Flow Calculator (DCF)

A discounted cash flow (DCF) calculator is a fundamental tool in equity analysis, enabling investors to estimate a stock’s intrinsic value by discounting projected future cash flows. Whether based on free cash flow to the firm (FCFF) or earnings per share (EPS), the DCF valuation calculator compares the computed fair value per share with the current market price to flag potential over‑ or under‑valuation. This free online stock valuation tool automates the core calculations, but understanding the underlying model is essential for sound investment decisions.

What Is the DCF Model?

The DCF method belongs to the income approach to valuation. It holds that the value of a business equals the sum of all cash flows it will generate in the future, each discounted to today using a rate that reflects the risk of those flows. The rationale is simple: owners and creditors invest capital in exchange for future returns (dividends, debt repayments, or reinvestment gains). Therefore, to assess whether a stock is worth its current price, one must estimate the present value of the cash flows the company can deliver.

The DCF model requires two primary inputs: a measure of cash flow (FCFF or EPS) and a discount rate that accounts for the time value of money and risk. The discount rate most often used with FCFF is the weighted average cost of capital (WACC), which blends the cost of equity with the after‑tax cost of debt. If free cash flow to equity (FCFE) were used instead, the cost of equity would be the appropriate rate.

FCFF‑Based DCF Formula

When using free cash flow to the firm, the total enterprise value is expressed as:

$$\text{Enterprise Value} = \sum_{t=1}^{n} \frac{FCFF_t}{(1+WACC)^t} + \frac{TV}{(1+WACC)^n}$$

Here $FCFF_t$ is the free cash flow to the firm in year $t$, $n$ is the length of the explicit projection period (typically 5–7 years), and $WACC$ is the weighted average cost of capital. The terminal value ($TV$) captures all cash flows beyond the projection horizon and is computed with the perpetual growth model:

$$TV = \frac{FCFF_n \times (1 + g)}{WACC - g}$$

In this expression, $g$ is the long‑term sustainable growth rate, often chosen between 2% and 3% to align with economic growth expectations. After obtaining the enterprise value, the equity value is derived by subtracting net debt (total debt minus cash). Finally:

$$\text{Fair Value per Share} = \frac{\text{Equity Value}}{\text{Shares Outstanding}}$$

The FCFF calculator component of the tool handles these steps automatically, allowing users to focus on assumptions.

EPS‑Based DCF Approach

For valuations that concentrate on net earnings, the intrinsic value is separated into a growth phase and a terminal phase. Let $EPS$ be the current earnings per share, $g$ the growth rate during the explicit period, $r$ the discount rate (WACC), $g_t$ the terminal growth rate, $n$ the number of growth years, and $m$ the number of terminal years. Then:

$$\text{Growth Value} = EPS \times \sum_{t=1}^{n} \left( \frac{1+g}{1+r} \right)^t$$ $$\text{Terminal Value} = EPS \times \left( \frac{1+g}{1+r} \right)^n \times \sum_{i=1}^{m} \left( \frac{1+g_t}{1+r} \right)^i$$

The intrinsic value is the sum of these two components. A fair value per share calculator using EPS is especially useful when a company’s net earnings are more stable than its operating cash flows.

Worked Example: FCFF Valuation

Consider Company Alpha with the following projected FCFF:

Year	FCFF (USD)
1	90,000
2	100,000
3	108,000
4	116,200
5	123,490

Assume WACC = 9.94% and perpetual growth $g = 4.48\%$.

First, compute the terminal value:

$$TV = \frac{123,490 \times (1 + 0.0448)}{0.0994 - 0.0448} = \$2,363,046.74$$

Discounting all cash flows back to the present yields an enterprise value of $1,873,573.51. Company Alpha holds$100,000 in cash and $900,000 in debt, so net debt is$800,000. This gives an equity value of $1,073,573.51. With 100,000 shares outstanding, the fair value per share is$10.74. If the current market price is $5.00, the stock is undervalued by roughly 114.7%, implying it would need to more than double to reach its DCF‑based fair value.

Worked Example: EPS Valuation

Imagine a startup trading at $300 per share with a trailing EPS of$50. Management expects 8% annual growth for the next five years, after which terminal growth of 3% is assumed for another five years. WACC is set at 11%.

Using the EPS formulas (values approximated):

• Growth value: 50 \times \sum_{t=1}^{5} (1.08/1.11)^t \approx \202.90$
• Terminal value: 50 \times (1.08/1.11)^5 \times \sum_{i=1}^{5} (1.03/1.11)^i \approx \202.70$

The intrinsic value sums to about $405.60, which is above the$300 purchase price, so the investment appears attractive. However, the growth value alone is below $300, meaning the first five years do not produce a profit; the terminal value is necessary to reach a positive return. This illustrates how terminal value calculator outputs often dominate DCF results for growth‑stage companies.

Interpreting DCF Results

DCF is not a crystal ball; its output is only as reliable as the inputs. Two key points to remember:

1. Comparison with market price: A fair value per share greater than the current price suggests undervaluation (and vice versa). Always consider a margin of safety because forecasts are uncertain.
2. Sensitivity to assumptions: Even a 1% change in WACC or the perpetual growth rate can alter fair value by a large percentage. Therefore, treat the DCF result as a range rather than a single precise number.

Important Caveats and When to Avoid DCF

The DCF model has a few mathematical constraints and practical limitations.

• WACC cannot equal the perpetual growth rate: The terminal value formula divides by $WACC - g$; if the two are equal, the result is undefined. Moreover, a perpetual growth rate that high would be unrealistic for any business.
• Negative free cash flows: While negative FCFF can be used in the projection period, the terminal value must be based on positive cash flows. A perpetually negative FCFF leads to a meaningless negative valuation.
• Dividend‑paying companies: If a firm pays substantial dividends (payout ratio above 20%), the dividend discount model may be more appropriate than a standard DCF.
• Unstable or high‑growth firms: Companies with unpredictable cash flows or aggressive expansion may produce unreliable DCF estimates. In such cases, relative valuation or asset‑based methods offer alternatives.

A stock valuation calculator based on DCF remains one of the most rigorous ways to estimate intrinsic value, but it is most effective when applied to mature, stable businesses with transparent financials and reasonable growth projections.