Binary Multiplication Calculator

About this calculator

Multiplying two binary numbers follows the same shift-and-add long multiplication method you’d use for decimal numbers, but it is simpler because every digit is either 0 or 1: each partial product is either all zeros or an exact shifted copy of the multiplicand, with no multiplication table to memorize. Those partial products are then added together (with binary carrying) to get the final result, which the calculator also converts to decimal so you can verify it.

This shift-and-add process is exactly how multiplication circuits work at the hardware level inside a CPU’s arithmetic logic unit (ALU) — binary multipliers in silicon are literally built from shifters and adders performing this operation. It is a core topic in computer science and digital logic courses, where students learn binary arithmetic before moving on to how processors implement it in hardware.

Enter two binary numbers and this calculator multiplies them step by step, showing the result in both binary and decimal.