Two's Complement Calculator

How it works

Two's complement is how signed integers are stored in binary: non-negative values are their plain binary form, and a negative value v at width n is stored as 2n + v. The top bit works out to be 1 for every negative value and 0 for every non-negative one, which is why it is often called the sign bit. All arithmetic here uses BigInt, so 64-bit values are exact — a plain Number starts losing precision above 2⁵³, well inside the 64-bit range.