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Hex to Decimal Converter

Read hexadecimal values as decimal numbers, unsigned or as signed two’s complement integers of 8 to 64 bits.

Processed locally in your browser

Options

Signed reads the top bit as the sign (two’s complement). Shorter inputs are zero-extended to the chosen width.

One number per line. Spaces and underscores inside a number are ignored.0 chars · 0 lines
The result will appear here.

What is Hex to Decimal Converter?

Each hexadecimal digit stands for four bits, with A to F meaning 10 to 15, and each position is worth a power of 16: 0xFF is 15 × 16 + 15 = 255. This tool computes the exact decimal value of hex strings of any length, including 256-bit numbers such as hashes or keys.

A leading 0x, spaces and underscores are ignored, so values pasted from code or dumps work as they are. Choose a signed width to read the pattern as two’s complement: FF is 255 unsigned but −1 as signed 8-bit, and FFFFFFFF is −1 as a signed 32-bit integer.

How does it work?

  1. Paste one hex value per line, with or without 0x; case does not matter.
  2. Keep “Unsigned”, or choose a signed 8, 16, 32 or 64-bit interpretation.
  3. Optionally choose a thousands separator for readability.
  4. Copy the decimals; a single value also shows binary and octal.

Common use cases

  • Reading an error code such as 0xC0000005 as a decimal or signed value.
  • Converting a 256-bit hash or key to its numeric value.
  • Checking memory addresses, offsets and sizes shown in hex in a debugger.
  • Decoding signed values from a binary protocol dump.

Examples

Try this input in the tool above:

Input
0xFF
DEADBEEF
ffff_ffff_ffff_ffff_ffff
Output
255
3735928559
1208925819614629174706175

Privacy

Hex to Decimal Converter runs entirely in your browser. The text or files you provide are processed on your device and are not uploaded, logged or stored on our servers.

Limitations

A signed interpretation needs the value to fit the chosen width. Hex is read as a number, not as text: to convert hex bytes to characters use the Hex to Text tool. Fractions are not accepted.

Frequently asked questions

Is 0xFF 255 or −1?

Both, depending on interpretation: 255 unsigned, −1 as a signed 8-bit two’s complement value. Select the signed width that matches your data type.

Does the case of the letters matter?

No. ff, FF and Ff all mean 255.

How large a hex number can I convert?

Thousands of digits. The conversion is exact because it uses arbitrary-precision integers.

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