Investment YieldT-Bill = [(F − P)/P] x [365 or 366/t]
The investment yield on a T-bond or T-note held to maturity can be approximated with the following formula, where r is the nominal rate, F is face value, P is purchase price, and y is years to maturity:
Investment YieldT-Bond = [r + [(F − P)/y]/[(F + P)/2]
To convert the effective annual yield (EAY) on an annual-pay bond (annual-pay YTM) to a bond equivalent yield for comparison with the semiannual-pay YTM of T-notes and T-bonds, the following equation is applied:
BEYEAY = [(1 + EAY)0.5 – 1] x 2