WACC Calculator (Weighted Average Cost of Capital)
This advanced WACC calculator supports multiple industry-standard methods: market-value vs book-value weightings, CAPM-based cost of equity, net vs gross debt treatment, and an adjustable private-company premium. Use the method selector to choose the approach that matches your appraisal or valuation process.
Results are numeric estimates based on user inputs. Inputs expressed as percentages should be entered as percent values (for example, enter 6 for 6%). The calculator converts percentage inputs internally to decimals when computing WACC.
Governance
Record bb99935d34a9 • Reviewed by Fidamen Standards Committee
Uses market capitalization for equity and net debt (debt minus cash). Cost of equity is estimated by CAPM using user inputs for risk-free rate, beta, and equity risk premium.
Inputs
Advanced inputs
Book-value inputs
Results
WACC (%)
774.17%
Cost of equity (CAPM) (%)
8.50%
After-tax cost of debt (%)
3.95%
Equity weight (%)
83.33%
Debt weight (%)
16.67%
| Output | Value | Unit |
|---|---|---|
| WACC (%) | 774.17% | % |
| Cost of equity (CAPM) (%) | 8.50% | % |
| After-tax cost of debt (%) | 3.95% | % |
| Equity weight (%) | 83.33% | % |
| Debt weight (%) | 16.67% | % |
Visualization
Methodology
Weights: either market-value weights (equity market capitalization and debt) or book-value weights (accounting figures). Net debt = total debt minus cash when net-debt mode is selected.
Cost of equity (CAPM): cost_of_equity = risk-free rate + beta × equity risk premium. For private companies, an additive premium may be applied to CAPM to reflect size, illiquidity, and control considerations.
Cost of debt: use pre-tax cost of debt and apply the tax shield by multiplying by (1 - tax rate). WACC is the weighted sum of the equity and after-tax debt costs.
Worked examples
Example 1 (public company, market-value, net debt): market cap 100m, net debt 10m, cost of equity 8%, pre-tax cost of debt 4%, tax 21% → compute weights and apply formula to get WACC.
Example 2 (private company): apply a private-company premium (e.g., 2%) to CAPM cost of equity to reflect higher expected return requirements; recompute WACC using the adjusted cost of equity.
F.A.Q.
Should I use market values or book values for weights?
Market values are preferred for valuations because they reflect current investor expectations. Book values may be used for accounting or regulatory contexts. Choose the approach consistent with your valuation purpose.
How should I input percentages?
Enter percentage inputs as whole numbers (for example, enter 6 for 6%). The calculator converts these to decimal fractions internally when computing.
Does this tool compute CAPM automatically?
Yes. When using CAPM methods, provide the risk-free rate, beta, and equity risk premium. The tool computes cost of equity = risk-free rate + beta × equity risk premium.
Are the results authoritative tax or accounting advice?
No. Calculations are estimates to support analysis and decision-making. Consult tax, accounting, or legal professionals for authoritative guidance. See the accuracy and compliance notes.
What are the limitations and accuracy considerations?
Outputs depend entirely on input accuracy and method selection. Model assumptions (e.g., CAPM validity, choice of ERP, beta adjustments) materially affect results. Rounding, data quality, and method selection introduce additional uncertainty. Use sensitivity checks and scenario analysis to validate results.
How should I treat private-company adjustments?
Private-company premiums are judgmental and vary by industry, size, and liquidity. Use market comparables, documented studies, or professional appraisal guidance when selecting a premium and disclose assumptions.
How are tax shields treated?
This calculator applies the corporate tax rate to the cost of debt to reflect the tax shield: after-tax cost of debt = pre-tax cost of debt × (1 - tax rate). Confirm the applicable tax rate for the entity and jurisdiction.
Sources & citations
- NIST — Framework and software assurance guidance — https://www.nist.gov
- ISO 31000 — Risk management — https://www.iso.org/iso-31000-risk-management.html
- IEEE — Software and systems engineering standards — https://www.ieee.org
- OSHA — Workplace safety standards (engineering governance reference) — https://www.osha.gov
- U.S. SEC — Guidance on valuation and disclosures — https://www.sec.gov
- SEC — Non-GAAP Financial Measures Guidance — https://www.sec.gov/corpfin/non-gaap-financial-measures
- FASB — Financial Accounting Standards Board — https://www.fasb.org/
- CFA Institute — Global Investment Performance Standards (GIPS) — https://rpc.cfainstitute.org/gips-standards
Further resources
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: bb99935d34a9What changed (latest)
v1.0.0 • 2025-11-06 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
What changed (latest)
v1.0.0 • 2025-11-06 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Engine
v1.0.0
Data
Baseline (no external datasets)
Content
v1.0.0
UI
v1.0.0
Governance
Last updated: Nov 6, 2025
Reviewed by: Fidamen Standards Committee (Review board)
Credentials: Internal QA
Risk level: low
Reviewer profile (entity)
Fidamen Standards Committee
Review board
Internal QA
Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person
Semantic versioning
- MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
- MINOR: New features or fields that do not change existing outputs for the same inputs.
- PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.
Review protocol
- Verify formulas and unit definitions against primary standards or datasets.
- Run golden-case regression suite and edge-case suite.
- Record reviewer sign-off with credentials and scope.
- Document assumptions, limitations, and jurisdiction applicability.
Assumptions & limitations
- Uses exact unit definitions from the Fidamen conversion library.
- Internal calculations use double precision; display rounding follows the unit's configured decimal places.
- Not a substitute for calibrated instruments in regulated contexts.
- Jurisdiction-specific rules may require official guidance.
Change log
v1.0.0 • 2025-11-06 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 0fe3c04439da