Discounted Cash Flow Calculator (DCF)

What is discounted cash flow (DCF)?

Discounted cash flow (DCF) is a valuation method that estimates the intrinsic value of an investment by projecting future cash flows and discounting them back to their present value. It's based on the principle that money today is worth more than the same amount in the future due to its potential earning capacity.

DCF analysis is considered one of the most thorough valuation methods because it focuses on actual cash generation rather than accounting earnings or market comparisons.

The DCF formula

The basic DCF formula is:

$$\text{DCF Value} = \sum_{t=1}^{n} \frac{CF_t}{(1+r)^t} + \frac{TV}{(1+r)^n}$$

Where:

• CF_t = Cash flow in year t
• r = Discount rate (WACC)
• n = Number of forecast years
• TV = Terminal value

Two-stage DCF model

Most DCF analyses use a two-stage approach:

Stage 1: Explicit forecast period

Project cash flows for 5-10 years with specific growth assumptions:

$$CF_t = CF_0 \times (1 + g)^t$$

Where g is the expected growth rate.

Stage 2: Terminal value

Calculate the value of all cash flows beyond the forecast period using the Gordon Growth Model:

$$TV = \frac{CF_{n+1}}{r - g_{terminal}}$$

Where g_terminal is the perpetual growth rate (typically 2-4%).

Key inputs explained

Cash flow

Use free cash flow (FCF), which represents cash available after operating expenses and capital expenditures:

$$\text{FCF} = \text{Operating Cash Flow} - \text{Capital Expenditures}$$

For stock valuation, use free cash flow to equity (FCFE) or free cash flow to firm (FCFF).

Discount rate (WACC)

The weighted average cost of capital reflects the required return for investors:

$$\text{WACC} = \frac{E}{V} \times r_e + \frac{D}{V} \times r_d \times (1 - T)$$

Company type	Typical WACC
Large-cap stable	7-10%
Mid-cap growth	10-12%
Small-cap	12-15%
Startup/High-risk	15-25%

Growth rate

The expected annual growth rate during the forecast period should reflect:

• Historical revenue growth
• Industry growth rates
• Competitive position
• Market opportunities

Terminal growth rate

The perpetual growth rate after the forecast period should be:

• Equal to or less than long-term GDP growth
• Typically 2-4% for mature companies
• Never exceed the discount rate

Example DCF calculation

Valuing a company with $1 million initial cash flow:

Input	Value
Initial cash flow	$1,000,000
Growth rate	15%
Discount rate	12%
Terminal growth	3%
Forecast years	5

Year-by-year projection

Year	Cash flow	Discount factor	Present value
1	$1,150,000	1.12	$1,026,786
2	$1,322,500	1.25	$1,054,323
3	$1,520,875	1.40	$1,082,610
4	$1,749,006	1.57	$1,111,664
5	$2,011,357	1.76	$1,141,502

Sum of present values: $5,416,885

Terminal value

$$\begin{aligned} TV &= \frac{\$2,011,357 \times 1.03}{0.12 - 0.03} \\ &= \frac{\$2,071,698}{0.09} \\ &= \$23,018,867 \end{aligned}$$

Present value of terminal: $23,018,867 ÷ 1.76 = $13,064,128

Total DCF value: $18,481,013

Sensitivity analysis

DCF valuations are highly sensitive to input assumptions. A small change in discount rate or terminal growth can significantly impact value:

Discount rate	Terminal growth 2%	Terminal growth 3%	Terminal growth 4%
10%	$22.5M	$27.3M	$35.2M
12%	$16.4M	$18.5M	$21.4M
14%	$12.6M	$13.8M	$15.3M

When to use DCF

DCF works best when:

• Cash flows are predictable and positive
• The company has stable operations
• You can reasonably forecast 5+ years
• The business is a going concern

DCF limitations

Input sensitivity

The principle of "garbage in, garbage out" applies strongly to DCF. Small changes in assumptions can dramatically change the valuation.

Terminal value dominance

Terminal value often represents 50-80% of total DCF value, making the model heavily dependent on perpetual growth assumptions.

Difficulty with unprofitable companies

DCF doesn't work well for:

• Startups with negative cash flows
• Cyclical businesses
• Companies in distress
• Rapid growth companies with uncertain futures

DCF vs other valuation methods

Method	Basis	Best for
DCF	Future cash flows	Stable, cash-generating businesses
P/E ratio	Earnings multiple	Quick comparison with peers
P/S ratio	Revenue multiple	Growth companies
P/B ratio	Book value	Asset-heavy businesses
EV/EBITDA	Operating earnings	M&A analysis

Margin of safety

When using DCF for investment decisions, apply a margin of safety:

$$\text{Target price} = \text{DCF value} \times (1 - \text{Margin of safety})$$

Common margins of safety:

• Conservative: 25-30%
• Moderate: 15-20%
• Aggressive: 10%

Professional tips

Use scenario analysis

Run multiple DCF scenarios:

• Base case — Most likely assumptions
• Bull case — Optimistic assumptions
• Bear case — Conservative assumptions

Validate assumptions

Cross-check your growth assumptions against:

• Industry benchmarks
• Historical performance
• Analyst estimates
• Management guidance

Consider alternatives

Use DCF alongside relative valuation methods to triangulate fair value. If DCF gives a vastly different value than comparables, investigate why.

Update regularly

DCF models should be updated as new information becomes available, including quarterly earnings, industry changes, and macroeconomic shifts.