Discounted Cash Flow (DCF) Valuation Calculator
Forecast annual free cash flows, a discount rate and a terminal growth rate, then compute the enterprise value via discounting.
輸入資料
計算結果
重點速覽：DCF values a firm by discounting forecast free cash flows and adding a terminal value. PV(FCF_t) = FCF_t/(1+r)^t; terminal value TV = FCF_last x (1+g)/(r-g) with g < r; EV = sum PV(FCF) + PV(TV). TV usually dominates (example ~79% of value). Example: 3y of 100k, r=10%, g=2% → EV ≈ 1.21m, TV PV ≈ 958k (~79%). WARNING: Highly assumption-sensitive; g must be < r; garbage-in-garbage-out; terminal value dominates, so stress-test g and r; pair with multiples. Education, not advice.
計算公式
預測現金流現值 = Σ Cᵢ ÷ (1 + r)^i，i 由 1 至 n。
永續終值 (Gordon 模型) = C_n × (1 + g) ÷ (r − g)，其中 g 為永續增長率、須 r > g。
終值現值 = 終值 ÷ (1 + r)^n；估值 = 預測現金流現值 + 終值現值。
$$\text{估值} = \sum_{i=1}^{n} \dfrac{C_i}{(1+r)^i} + \dfrac{1}{(1+r)^n} \cdot \dfrac{C_n(1+g)}{r-g}$$使用說明
- Enter forecast free cash flows for years 1-5 (0 to end early).
- Enter the discount rate (WACC/required return).
- Enter a terminal growth rate below the discount rate.
- View EV, PV of cash flows and PV of terminal value.
預測 3 年現金流 100,000 / 110,000 / 120,000、永續增長率 g = 2%，在不同折現率下的估值拆解
| 折現率 r | 現金流現值 | 永續終值 | 終值現值 | 總估值 |
|---|---|---|---|---|
| 8% | HK$282,160 | HK$2,040,000 | HK$1,619,418 | HK$1,901,578 |
| 10% | HK$271,976 | HK$1,530,000 | HK$1,149,512 | HK$1,421,488 |
| 12% | HK$262,391 | HK$1,224,000 | HK$871,219 | HK$1,133,610 |
| 15% | HK$249,034 | HK$941,538 | HK$619,077 | HK$868,111 |
理財情境案例
案例一：估算一盤生意的內在價值
投資者評估收購一盤生意，預測未來 3 年自由現金流分別為 HK$500,000、HK$550,000、HK$600,000，要求回報率 (折現率) 12%，並假設之後現金流以永續增長率 3% 持續增長。
3 年現金流現值約為 HK$1,311,953；以第 3 年現金流套用 Gordon 模型得永續終值約 HK$6,866,667，折現回現值約 HK$4,887,558。兩者相加，這盤生意的估值約為 HK$6,199,511。若賣方開價明顯低於此數，理論上有折讓空間。
案例二：終值主導估值的警示
以預測 3 年各 HK$100,000 現金流、折現率 10%、永續增長率 2% 計算，總估值約為 HK$1,206,612，其中終值現值約 HK$957,926，佔總估值高達約 79.4%。
這說明 DCF 的估值幾乎由「預測期之後」的終值主導，而終值又對永續增長率與折現率極度敏感。若把永續增長率由 2% 上調至 3%，或折現率下調 1%，估值都會顯著跳升。因此使用 DCF 時，不應盲信單一數字，而要檢視終值假設是否合理。
常見問題
What is DCF and the key formulas?
DCF discounts forecast future free cash flows (FCF) to today and adds a terminal value (TV). PV(FCF_t) = FCF_t/(1+r)^t; TV = FCF_last x (1+g)/(r-g) (Gordon growth, g < r); EV = sum of PV(FCF) + TV/(1+r)^n. TV usually dominates the value (often 60%-80%).
Why is the terminal value so important?
Because most of a firm's value comes from cash flows beyond the explicit forecast (the going concern). In the example, TV PV is ~79% of EV — small errors in g or r cascade into huge value swings. That is why you must sanity-check the terminal assumptions and run sensitivity.
How do I choose the discount rate and g?
Discount rate: usually WACC (blend of equity and debt cost, see the WACC calculator), or a required return reflecting risk. g: a perpetual growth rate, must be below r and ideally below long-term GDP/nominal growth (e.g. 2%-3%) — setting g near r explodes TV. Use conservative, defensible values and stress-test.
Is DCF reliable, and what are its limits?
DCF is rigorous but 'garbage in, garbage out' — it hinges on forecasts, r and g. Errors compound, and TV dominates, so a small assumption change swings value a lot. It is best paired with comparables/multiples (P/E, EV/EBITDA) and scenario analysis. Treat the output as a range, not a point.
How should Hong Kong / growth companies use DCF?
HK-listed and growth firms often have volatile or negative near-term FCF, making DCF hard but still useful for long-horizon valuation. Tips: forecast on a reasonable base (normalised FCF), keep horizon long enough for maturity, keep g conservative and below r, and show scenarios (bull/base/bear). Note HK market pricing also leans on comparables and dividends; DCF should complement, not replace, multiples. For listed names, cross-check with the market-cap and dividend-discount calculators. Education, not advice.
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參考資料
內容審核：香港計算器財經團隊。計算邏輯與公式參考香港金融管理局（HKMA）及投資者及理財教育委員會（IFEC）之個人理財計算指引，結果僅供參考，實際以相關機構公佈為準。