# Estimation of Default Probability from Bond

Typically the formula to calculate the default probability from corporate Bond looks like

$$\frac{S}{1-R}$$

where $$S$$ is the spread of Corporate bond yield over the RFR and $$R$$ is recovery rate.

I failed to understand the intuition behind this formula. Why this formula refers to the default probability?

This might be very trivial, but I really appreciate for any insight on the reasoning.