Hexadecimal (base 16) uses digits 0–9 and letters A–F. It is widely used in computing for memory addresses, colour codes (#RRGGBB), and byte representations.

Does it accept the 0x prefix?

Yes. You can enter values with or without the 0x prefix: 'FF' and '0xFF' are treated as the same number.

Is the conversion case-sensitive?

Case does not matter. 'ff', 'FF', and 'Ff' are all equivalent hexadecimal values.

How do I convert hex to decimal by hand?

Multiply each digit by 16 raised to its position, counting from 0 on the right, and add the results. 0x1A3 is 1×256 + 10×16 + 3 = 419.

Hex to decimal converter

Enter a hexadecimal number (base 16) to instantly see its decimal, binary, and octal equivalents. Accepts hex values with or without the 0x prefix.

HEX input (base 16)

BIN–

OCT–

DEC–

HEX–

INPUT BASE

All bases shown simultaneously.

Runs entirely in your browser

Worked example

Multiply each digit by 16 raised to its position: 0x1A3 = 1×256 + 10×16 + 3 = 419. The same value is 110100011 in binary and 643 in octal.

How it works

The input is checked digit by digit and turned into a JavaScript BigInt, then written out with BigInt.prototype.toString(base), so large values stay exact. All four bases are computed simultaneously from the same input value, so you can see binary, octal, decimal, and hex at a glance.

Processing runs in your browser

All conversion runs in your browser tab. Our servers are not involved at any point.

Related operations

For converting between data sizes like KB and MB, try the byte converter. To compute MD5 or SHA hashes from values, use the hash generator. For working with file permission bits, see the chmod calculator.

Frequently asked questions

What is hexadecimal?: Hexadecimal (base 16) uses digits 0–9 and letters A–F. It is widely used in computing for memory addresses, colour codes (#RRGGBB), and byte representations.
Does it accept the 0x prefix?: Yes. You can enter values with or without the 0x prefix: 'FF' and '0xFF' are treated as the same number.
Is the conversion case-sensitive?: Case does not matter. 'ff', 'FF', and 'Ff' are all equivalent hexadecimal values.
How do I convert hex to decimal by hand?: Multiply each digit by 16 raised to its position, counting from 0 on the right, and add the results. 0x1A3 is 1×256 + 10×16 + 3 = 419.

Last reviewed September 30, 2026

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