How to use the Hex to Decimal
Convert hex to decimal in two steps:
1
Enter the hex number
Type or paste any hexadecimal number using digits 0–9 and letters A–F (case-insensitive). The 0x or 0X prefix is optional and stripped automatically.
2
Read the decimal result
The decimal equivalent appears instantly. The byte-grouped hex display and equivalent binary/octal are shown in the panel below.
When to use this tool
Use to read and interpret hexadecimal values in programming and system contexts:
- →Converting hex color codes (like #FF5733) to their decimal RGB component values for CSS or image processing work
- →Reading hex memory addresses from a debugger, crash dump, or linker map file as decimal offsets
- →Interpreting hex error codes from Windows (0x80070005), macOS, or Linux kernel output as decimal values
- →Converting hex values from hardware register documentation to decimal for comparison with measured sensor readings
- →Translating hex ASCII character codes (e.g. 0x41 = 65 = 'A') when working with binary protocols or file formats
- →Decoding hex-encoded integer values in JSON, XML, or binary protocol payloads for debugging
Frequently asked questions
Q:How does hex to decimal conversion work?
Each hex digit represents a power of 16, starting from 16⁰ (= 1) at the rightmost position. Hex digits A–F represent decimal values 10–15. To convert, multiply each digit's value by its positional power of 16 and sum the results. For example, 0xFF = 15×16¹ + 15×16⁰ = 240 + 15 = 255. The tool uses JavaScript BigInt to handle hex numbers of any length precisely, converting them digit by digit in a single pass.
Q:Is the tool case-sensitive for hex input?
No — the tool accepts lowercase (ff, deadbeef), uppercase (FF, DEADBEEF), and mixed-case (DeadBeef) hex input equally. All input is normalised to uppercase before conversion. This matches standard practice — both uppercase and lowercase are valid hex representations in most programming languages and protocols.
Q:Do I need to include the 0x prefix?
No — the 0x prefix (or 0X) is optional and stripped automatically if present. You can paste hex values with or without the prefix: 'FF', '0xFF', '0XFF', and '0xff' all convert identically. This makes it easy to paste hex values directly from any source without editing.
Q:What does the byte grouping display show?
The byte grouping display shows the hex value as pairs of two hex digits, each pair representing one byte (8 bits). For example, 0xDEAD is shown as 'DE AD' — two bytes. This grouping matches how hex values are typically shown in memory editors, packet captures, and hex dumps, where each byte is represented by exactly two hex digits separated by spaces.
Q:How do hex color codes relate to decimal?
An HTML/CSS hex color like #FF5733 consists of three 2-digit hex components: FF (red), 57 (green), 33 (blue). Each component is one byte (0–FF = 0–255 decimal). FF hex = 255 decimal (maximum red), 57 hex = 87 decimal, 33 hex = 51 decimal. So #FF5733 in RGB decimal is rgb(255, 87, 51). Convert each 2-digit hex pair individually to get the RGB decimal values.
Q:What is the decimal value of 0xFF and why is it common?
0xFF = 255 in decimal. It is one of the most frequently encountered hex values in computing because it represents 11111111 in binary — all 8 bits set in a single byte. It appears as the maximum unsigned byte value, the maximum RGB channel value, the 255.255.255.255 IPv4 broadcast address (each octet is 0xFF), single-byte bitmasks, and the maximum value for many 8-bit hardware registers.