How the Unlevered Beta Calculator works
Equity beta — the beta quoted for a public stock — bundles two things together: the underlying business risk of the company's operations, and the extra risk added by its debt load. Unlevered beta, also called asset beta, strips out that financing effect, leaving only the risk that comes from the business itself. This calculator applies the standard Hamada equation to convert a levered (equity) beta into an unlevered beta, then relevers the result at a target debt-to-equity ratio.
The formula
For a levered beta βL, a marginal tax rate Tax, and a debt-to-equity ratio D/E (total debt divided by the market value of equity), the unlevered beta is:
βU = βL / (1 + (1 − Tax) × D/E)
The (1 − Tax) term reflects the tax shield on interest: because interest payments are tax-deductible, debt adds less systematic risk to equity than its face amount alone would suggest. The formula assumes the beta of debt is zero — debt is treated as carrying no systematic risk — which is the standard simplifying assumption behind the Hamada equation, developed by combining Modigliani-Miller capital structure theory with the CAPM.
Relevering the beta
Once you have an unlevered beta, you can relever it at a different capital structure by running the formula in reverse:
Beta at target D/E = βU × (1 + (1 − Tax) × target D/E)
This unlever-then-relever process is the standard way analysts compare companies with different amounts of debt. A common workflow: pull the equity betas of several comparable companies, unlever each one to remove the distortion from its own capital structure, average the resulting asset betas, then relever that average at the target company's own (or a planned) D/E ratio to estimate the beta that belongs in a CAPM cost-of-equity calculation.
Worked example
Take a company with a levered beta of 1.20, $400 million of total debt, $600 million of market equity value, and a 21% tax rate. The debt-to-equity ratio is 400 / 600 ≈ 0.67x. Unlevering gives βU = 1.20 / (1 + 0.79 × 0.67) ≈ 1.20 / 1.53 ≈ 0.78. Relevering that 0.78 asset beta at a target D/E of 0.50x gives 0.78 × (1 + 0.79 × 0.50) ≈ 1.09 — lower than the original 1.20 because the target capital structure carries less debt.
Why unlevering matters
- Removing financing noise: two companies with identical operations but different debt loads will show different equity betas. Unlevering puts them on the same footing before comparison.
- More debt raises levered beta: for a company with positive operating risk, adding debt amplifies the equity beta, because fixed interest obligations make equity cash flows more volatile relative to firm cash flows.
- Zero debt beta is a simplification: real corporate debt does carry some systematic risk, especially for highly leveraged or distressed borrowers. Some practitioners substitute a small positive debt beta in those cases, though the zero-beta assumption remains the textbook standard.
Assumptions and limits
This calculator assumes a constant marginal tax rate, a debt beta of zero, and that market (not book) values are used for debt and equity where available. Preferred stock, operating leases, and other hybrid claims are not modeled separately, so if a company carries significant amounts of these, treat the result as an approximation. The output is a computation only, not investment or financial advice — pair it with your own judgment or a qualified professional for decisions that matter.