The beta of a company after subtracting out the impact of its debt obligations. Unlevered beta removes the effects of the use of leverage on the capital structure of a firm, since the use of debt can result in tax rate adjustments that benefit a company. Removing the debt component allows an investor to compare the base level of risk between various companies. It is calculated by dividing the levered beta by [1 + (1 - tax rate) x (D / E)], where D/E is the debt/equity ratio.