Hexadecimal Converter
This hexadecimal converter turns any whole decimal number into its hexadecimal equivalent, along with the matching binary and octal forms, so you can move between the number systems used throughout computing without working through the division and remainder steps by hand. Hexadecimal, base sixteen, uses the digits 0 to 9 then the letters A to F for the values ten to fifteen, and because each hex digit represents exactly four binary bits, it is the standard shorthand programmers use for byte values, memory addresses, colour codes and other data that is naturally binary underneath. You simply enter a decimal whole number, and the calculator instantly returns the hexadecimal value in the main result, with the binary and octal equivalents shown alongside for reference. Negative numbers are handled too, with the sign carried across all three conversions. The worked example on this page shows 255 converting to FF in hex, 11111111 in binary and 377 in octal, so you can check the tool against a known value before trusting it with your own figures. It suits students learning number systems, programmers converting byte or colour values, and anyone curious about how computers represent numbers internally. The calculator uses the exact integer conversion rather than an approximation, so the result is precise for any whole number you enter, however large.
The formula
To convert to hexadecimal, repeatedly divide by 16 and record the remainders as hex digits (10 to 15 become A to F), then read them from last to first. Each hex digit represents four binary bits.
Worked example
255 divided by 16 is 15 remainder 15, and 15 is F, so 255 is FF in hex. That is also 11111111 in binary and 377 in octal. Enter 255 to confirm.
Frequently asked questions
What is hexadecimal?
Base sixteen, using digits 0 to 9 and letters A to F. It is a compact way to write binary, with one hex digit per four bits.
What is 255 in hex?
FF, the largest value of a single byte.
Why do programmers use hex?
Because it maps neatly to bytes and binary, and is shorter to read than long strings of 0s and 1s.
Who this calculator is for
This calculator is for students, programmers and anyone exploring number theory.
What this calculator assumes
- You enter a whole number within the stated range.
- The exact integer algorithm is used.
- Very large results are shown grouped for readability.
Formula and sources
Related calculators
- Prime Factorization Calculator: break a number into prime factors.
- LCM Calculator: lowest common multiple.
- GCF Calculator: greatest common factor.