Base Converter
Convert two numbers between any bases (2–36) side by side, live as you type — then add, subtract, multiply or divide them.
Number 1base 10
bin11111111
oct377
dec255
hexff
Number 2base 2
bin1010
oct12
dec10
hexa
Result255 + 10
bin100001001
oct411
dec265
hex109
About number bases
In base b every digit is worth a power of b: the decimal number 42 means 4×10 + 2, and in binary the same value is 101010 = 32 + 8 + 2. Bases beyond 10 use letters, so hex FF equals 255.
Converting to a new base repeatedly divides by b and collects the remainders bottom-up; converting back multiplies each digit by its place value. Both directions are exact integer arithmetic.
All arithmetic runs on BigInt, so huge values convert without the 32/64-bit overflow that limits calculator apps: 2^100 in binary is exact to the last digit.