Decimal to Hex Converter Online

Easily convert decimal numbers to hexadecimal notation. Our converter includes explanations and formatting options. A vital tool for low-level programming, memory addressing, and digital system design.

Decimal to Hex Converter

Convert decimal numbers (base-10) to hexadecimal (base-16)

Uppercase (A-F)

Padding:digits

No prefix0x prefix

Decimal Input

Hexadecimal Output

Conversion Examples

Decimal: 10

→ 0xA

Decimal: 16

→ 0x10

Decimal: 255

→ 0xFF

Decimal: 1000

→ 0x3E8

How it works

Enter a decimal number in the input field. The converter transforms it to hexadecimal format using division-by-16 method, displaying the result with or without the "0x" prefix based on your preference.

For negative numbers, toggle signed mode to see the two's complement representation. Choose your desired bit width (8, 16, 32, or 64 bits) to see how the number is represented in fixed-width binary systems.

The conversion happens instantly as you type. Large numbers are handled using BigInt arithmetic for full precision. Copy the hex result with one click for use in code, documentation, or further calculations.

When You'd Actually Use This

Programming Constants

Convert decimal values to hex for bitmasks, flags, and magic numbers in source code.

Color Conversion

Convert decimal RGB values (0-255) to hex color codes for web design and CSS.

Memory Addresses

Convert decimal memory offsets or addresses to hex for debugging and documentation.

Error Codes

Look up hexadecimal error codes and status values from decimal system outputs.

Hardware Configuration

Set register values, I/O addresses, and configuration parameters in hex format.

Math Education

Learn base conversion by seeing decimal-to-hex transformations with verification.

What to Know Before Using

Division method: Convert by repeatedly dividing by 16 and collecting remainders. Remainders 10-15 become A-F in hex.

Two's complement: Negative numbers in computers use two's complement. For -1 in 8-bit: invert all bits of 1, add 1, giving 0xFF.

Bit width matters: The same decimal value has different hex representations at different bit widths when negative. Positive values pad with leading zeros.

0x prefix: Many programming languages use "0x" to indicate hex literals. This is optional but helps distinguish from decimal.

Case convention: Hex letters are typically uppercase (A-F) in most technical contexts, though lowercase is equally valid.

Common Questions

What is 255 in hex?

255 in decimal equals 0xFF in hex. This is the maximum value for an 8-bit byte (all 8 bits set to 1).

How do I convert decimal to hex manually?

Divide by 16 repeatedly, tracking remainders. For 419: 419÷16=26 R3, 26÷16=1 R10(A), 1÷16=0 R1. Read remainders backward: 1A3.

What is -1 in hex?

In two's complement: 8-bit = 0xFF, 16-bit = 0xFFFF, 32-bit = 0xFFFFFFFF, 64-bit = 0xFFFFFFFFFFFFFFFF. All bits are 1.

How do I convert RGB to hex color?

Convert each RGB component (0-255) to 2-digit hex. RGB(255, 128, 64) = #FF8040. Pad single-digit results with leading zero.

Can I convert very large numbers?

Yes. The converter uses BigInt for arbitrary precision, handling numbers far beyond standard 64-bit limits.

Why does my hex have leading zeros?

Leading zeros indicate fixed bit width. 0x00FF is 16-bit representation of 255, showing it fits in 2 bytes with the high byte being zero.

What's the hex for 1024?

1024 in decimal equals 0x400 in hex. This is 2^10, a common value in computing (1 kilobyte in bytes).

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