WACC (Weighted Average Cost of Capital) is the minimum return a company must earn
on its existing assets to satisfy its capital providers — both equity holders and
debt holders. It serves as the hurdle rate for investment decisions and DCF valuations.
WACC formula
WACC = (E/V) × Rₑ + (D/V) × Rᵈ × (1 − Tᶜ)
Where:
- E = Market value of equity (market cap)
- D = Market value of debt
- V = E + D (total capital)
- Rₑ = Cost of equity (%)
- Rᵈ = Pre-tax cost of debt (%)
- Tᶜ = Corporate tax rate (%)
Cost of equity is usually estimated with CAPM: risk-free rate + beta × equity risk
premium. Beta measures how volatile a stock is relative to the overall market — a
beta of 1.5 means the stock tends to move 50% more than the market in either
direction, which investors demand a higher return for holding.
Why does the tax rate matter?
Debt interest is tax-deductible, which creates a "tax shield." The after-tax cost of
debt is Rᵈ × (1 − Tᶜ). A company with 6% cost of debt and 25% tax rate has an
effective debt cost of 4.5%.
Typical WACC benchmarks
Industry
Typical WACC
SaaS / Software
8–14%
Consumer goods
6–10%
Utilities
4–8%
Biotech
12–20%
WACC in practice
DCF valuations: WACC is the discount rate applied to future free cash flows
Capital budgeting: only accept projects with IRR > WACC
Capital structure decisions: optimise the mix of equity and debt to minimise WACC
Performance measurement: ROIC > WACC means the company creates economic value
WACC for Startup Valuation: What Discount Rate to Use
How to estimate WACC for early-stage startups — where public market comparables, beta, and risk premiums apply differently than for public companies.
WACC for startups is more art than science because the inputs — market cap, beta,
cost of debt — are either unavailable or unreliable. Here is how practitioners approach it.
Why traditional WACC breaks for startups
No market cap: equity value is private and highly uncertain
No beta: can't observe historical price volatility
Little or no debt: capital structure is mostly equity
High failure probability: DCF models don't capture binary outcomes well
How VCs think about discount rates
VCs rarely use WACC explicitly. Instead, they apply a target IRR of 30–50%+
(reflecting a 10x fund return target with expected failures). This is equivalent to
using a WACC of 30–50% — far above what traditional WACC models would suggest.
For DCF models
When building a DCF for a startup, practitioners typically:
- Use a peer group WACC from comparable public companies (usually 8–15% for SaaS)
- Add a size premium of 3–5% for private, smaller companies
- Add a company-specific risk premium of 3–10% for execution risk
Effective startup discount rate: 14–30% depending on stage and sector.
Use the WACC calculator for established companies with
observable equity and debt values.
Using WACC as Your DCF Discount Rate: A Practical Guide
How to use WACC as the discount rate in a DCF valuation — including how to estimate cost of equity for early-stage companies and common mistakes.
WACC (Weighted Average Cost of Capital) is the standard discount rate in DCF
(Discounted Cash Flow) valuations. Here is how to use it correctly and what to
do when textbook inputs aren't available.
WACC in DCF: the mechanics
In a DCF model:
Value = Σ (Free Cash Flow_t / (1 + WACC)^t) + Terminal Value / (1 + WACC)^n
WACC represents the required return for the entire capital structure — both equity
and debt holders. Discounting at WACC gives enterprise value; subtract net debt
to get equity value.
Estimating WACC for early-stage companies
Private companies and startups lack public market data for cost of equity. Approaches:
CAPM approach: Cost of equity = Risk-free rate + β × (Market premium)
- Risk-free rate: 10-year US Treasury yield (~4.5% in 2024)
- Equity risk premium: 5–6% (Damodaran historical)
- Beta: use comparable public company betas (0.8–1.5 for SaaS)
VC hurdle approach: use the fund's target IRR (25–40% for early stage) as the
cost of equity. This reflects the actual required return for equity investors.
No debt (pre-revenue): WACC = cost of equity. No debt weighting needed.
Common WACC mistakes
Using book value instead of market value for equity and debt weights
Not adjusting for taxes on the cost of debt component
Using WACC for highly levered or distressed companies — use adjusted
present value (APV) instead when debt levels change significantly over time
Use the WACC calculator to compute your blended
cost of capital for DCF analysis.