An interpolative digital-to-analog (D/A) converter is adapted to convert a N-bit digital signal into an analog signal, where N is a positive integer greater than 1. The interpolative D/A converter includes a router unit that outputs first and second router voltages based on the first and second bits of the digital signal, and an interpolation unit that receives the first and second router voltages from the router unit, and that performs interpolation operation on the first and second router voltages according to the first bit of the digital signal, so as to generate the analog signal having a voltage magnitude ranging from the first router voltage to the second router voltage.