Decimal to Hex Converter

What is Decimal to Hex Conversion?

Decimal to hexadecimal conversion changes a base-10 number (digits 0-9) into its base-16 equivalent, which uses digits 0-9 plus letters A-F to represent values 10 through 15. Converting decimal to hex is the basis for reading memory addresses, color codes, and byte values in a compact form.

For example, decimal 255 is the largest value a single byte can hold, and it equals hexadecimal FF. To convert the other direction, use the Hex to Decimal Converter. For the related base-2 conversion, see Decimal to Binary.

How to Convert Decimal to Hex Manually

The standard manual method is repeated division by 16:

Worked example: convert 255 to hexadecimal

255 ÷ 16 = 15 remainder 15 (F)
 15 ÷ 16 = 0  remainder 15 (F)

Reading remainders from bottom to top: FF

Therefore, 255 in decimal = FF in hexadecimal

Manual division is useful for understanding the mechanics, but it is easy to drop a remainder on longer numbers — the converter above returns the exact result for any size of input. For a fuller walkthrough with more worked examples, see How to Convert Decimal to Hex.

Hex Digit Reference (0-9, A-F)

Hexadecimal is base 16, so each digit position can hold 16 possible values. Decimal 0-9 use the same digits in hex; decimal 10-15 use the letters A-F.

Decimal to Hex Conversion Table

A quick reference for common decimal numbers and their hexadecimal equivalent:

Where Decimal to Hex Conversion Is Used

• Programming and debugging: memory dumps, pointers, and error codes are typically printed in hex because it maps cleanly onto bytes (2 hex digits = 1 byte).
• Memory addresses: operating systems and debuggers display addresses in hexadecimal for compact, unambiguous reading.
• Color and data representation: CSS/HTML color codes (such as #FF5733) are three hex byte pairs for red, green, and blue.
• Low-level systems: MAC addresses, hash digests, and binary file dumps are conventionally shown in hex rather than binary or decimal.
• Computer science education: converting between decimal, binary, and hex builds the base-conversion skills used throughout systems courses. The Decimal to Binary Converter covers the related base-2 case.

Negative Numbers and Two's Complement

This converter accepts zero and positive integers only. Simply writing a minus sign in front of a hex string (for example, -FF) isn't how computers represent negative numbers, and it isn't a fixed, unambiguous format on its own.

Machines represent negative numbers using two's complement, which requires choosing a fixed bit width (such as 8, 16, or 32 bits) before the hex representation makes sense. Use the Two's Complement Calculator to convert a negative decimal value into its signed representation at a specific bit width.

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Frequently Asked Questions