Hex Calculator

Hexadecimal to decimal, binary and octal.

Hexadecimal to decimal, binary and octal. Hexadecimal uses sixteen digits — 0 to 9 then A to F — so each one carries exactly four bits.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these

Value in hexadecimal

Decimal

597

10 bits

Decimal597

Binary1001010101

Octal1125

Hexadecimal255

Bits required10

Every base writes the same quantity differently — 597 is 1001010101 in binary and 255 in hex, and none is more correct than the others. Hexadecimal earns its place in computing because one hex digit is exactly four binary digits, so conversion between them needs no arithmetic at all.

How the Hex Calculator works

Hexadecimal uses sixteen digits — 0 to 9 then A to F — so each one carries exactly four bits. That is why it is the standard shorthand for binary data: colours, memory addresses and byte values all read more easily in hex than in eight-digit strings of ones and zeros.

Also known as: hex to decimal · decimal to hex converter · hexadecimal converter · hex to binary converter

Where to go next

The Hex question rarely arrives on its own. These are the ones that usually come with it:

Binary Calculator — Binary to decimal, hex and octal, with validation that works.
Octal Calculator — Octal to decimal, binary and hexadecimal.
Base Converter — Decimal into binary, octal and hexadecimal at once.
Percentage Calculator — Every common percentage question in one place.

Sources

NIST Digital Library of Mathematical Functions

Frequently asked questions

How do I convert hex to decimal?

Each place is worth sixteen times the one to its right. FF is 15 × 16 + 15 = 255.

What do the letters mean?

A through F stand for 10 through 15, the values that need a single digit in base 16 but two in base 10.

Why is hex used for colours?

Because each colour channel is one byte, which is exactly two hex digits. FF0000 is full red, no green, no blue.

How does hex relate to binary?

One hex digit is precisely four binary digits, so F is 1111 and FF is 11111111. Converting between them needs no calculation.

Put this calculator on your own site

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The one-line version

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