An extensible iterative multiplier design is provided. Embodiments provide cascaded 8-bit multipliers for simplifying the performance of multi-byte multiplications. Booth encoding is performed in the lowest order multiplier, with the result of the Booth encoding then provided to higher order multipliers. Additionally, multiply-add operations can be performed by initializing a partial product sum register. Configurable connections between the multipliers facilitate a variety of possible multiplication options, including the possibility of varying the width of the operands.