Binary to Decimal

A binary to decimal converter translates a base-2 number, written only with 0s and 1s, into the base-10 number system people use every day. Binary works by place value: each digit, read from right to left, represents a power of two, so the rightmost bit is worth 1, the next 2, then 4, 8, 16, and so on. To convert, you add up the place values wherever a 1 appears. The binary number 1011, for example, is 8 + 0 + 2 + 1 = 11 in decimal. This tool does that summation instantly for any length of input and shows the result, so you can check homework, debug a bit pattern, or read a value from a register dump without doing the arithmetic by hand. For signed numbers it interprets the input using two's complement, the standard way computers store negative integers. In an 8-bit two's complement byte, the leftmost bit is the sign: 11111111 is not 255 but -1, because the top bit carries a negative weight. This is a frequent source of confusion, since the same bit pattern means 255 when read as unsigned and -1 when read as signed, and the only difference is which interpretation you choose. The converter handles integer values; fractional binary, where digits after a binary point represent halves, quarters, and eighths, is not supported. Very large inputs are bounded by JavaScript's safe-integer limit of 2 to the 53 minus 1, beyond which precision degrades. Everything runs locally in your browser, so the values you convert are never uploaded. It pairs naturally with the Decimal to Binary tool for round-tripping a number in either direction.