Math Tools

Hex Calculator

Convert between hex, decimal, binary, and octal. Perform hexadecimal arithmetic.

Mode

Value

From

Converted Value

255

Decimal (Base 10)

HexadecimalFF

Decimal255

Binary11111111

Octal377

What is the Hex Calculator?

Hexadecimal (base 16) is a numbering system using digits 0–9 and letters A–F. It's widely used in computing for memory addresses, color codes (#FF5733), and data representation. This calculator converts hex to decimal, binary, and octal, and also performs addition, subtraction, multiplication, and division on hex values without manual conversion.

How it works

The calculator offers two modes. Arithmetic mode takes two hex values and an operation (add, subtract, multiply, divide) and computes the result in all four bases. Convert mode takes a single value, lets you specify its source base, and converts it to any target base (hex, decimal, binary, octal). Results display instantly with no manual calculation needed.

Hex conversion uses positional notation: each digit position represents a power of 16. For example, FF in hex = (15 × 16¹) + (15 × 16⁰) = 240 + 15 = 255 in decimal. Arithmetic operations follow standard addition, subtraction, multiplication, and integer division rules.

In hexadecimal, A=10, B=11, C=12, D=13, E=14, F=15. Each position left increases the power of 16. Arithmetic operations work the same way as decimal, but the result is expressed in whichever base you need.

Input	Result	Notes
Hex: FF converted to decimal	255	F = 15, so (15 × 16) + 15 = 255
Hex: 1A + 2B (arithmetic mode)	45 (hex), 69 (decimal)	26 + 43 in decimal = 69, which is 45 in hex
Decimal: 100 converted to hex	64	100 ÷ 16 = 6 remainder 4, so hex is 64

Input

Result

Notes

Hex: FF converted to decimal

255

F = 15, so (15 × 16) + 15 = 255

Hex: 1A + 2B (arithmetic mode)

45 (hex), 69 (decimal)

26 + 43 in decimal = 69, which is 45 in hex

Decimal: 100 converted to hex

100 ÷ 16 = 6 remainder 4, so hex is 64

How to use the Hex Calculator

Choose Arithmetic mode to add, subtract, multiply, or divide hex values; or Convert mode to change bases

For Arithmetic: enter two hex values, pick an operation, and get instant results in hex, decimal, binary, and octal

For Convert: enter any value, select its source base and target base, and view the conversion

Results display in the dark box with full breakdowns in the stats section below

Copy the result or try another calculation

Benefits

No manual conversion needed—instant results in all four bases simultaneously

Perfect for programmers working with color codes, memory addresses, and low-level data

Eliminates arithmetic errors when working with unfamiliar bases

Educational tool for students learning number systems and base conversion

Works offline and 100% client-side—your data never leaves your browser

Tips & common mistakes

Common mistakes

Using invalid hex characters—remember hex uses only 0–9 and A–F (case-insensitive)

Forgetting which base you are converting from—always confirm the source base before converting

Mixing bases in arithmetic—the calculator assumes both inputs are hex; convert first if needed

Dividing by zero—the calculator returns 0 if you try to divide by zero in arithmetic mode

Tips

Use uppercase hex (A–F) for clarity, though the calculator accepts lowercase too

Binary numbers can be very long; focus on decimal or hex for easier reading

Color codes in CSS (#FF5733) are hex; this calculator can break them into RGB equivalents

In programming, hex is often prefixed with 0x (e.g. 0xFF). The calculator accepts both with and without the prefix

Frequently asked questions

What is hexadecimal used for?

Hexadecimal is used in computing for memory addresses, color codes, file encoding, and data representation. It's compact (easier than binary) yet directly maps to groups of 4 binary digits.

What does 'A' through 'F' mean in hex?

In hexadecimal, A=10, B=11, C=12, D=13, E=14, F=15. These letters allow us to represent 16 unique digits using 0–9 and A–F.

Can I use the 0x prefix (like 0xFF)?

Yes. The calculator accepts hex values with or without the 0x prefix. Both FF and 0xFF will work.

What is the largest hex value the calculator can handle?

The calculator handles numbers up to JavaScript's maximum safe integer (about 9 quadrillion). Larger values may lose precision.

How do I convert RGB colors to hex?

This calculator converts between number bases. For RGB-to-hex color conversion, each color channel (R, G, B) is a decimal 0–255 value; convert each to hex separately and combine them (e.g. RGB 255,127,0 = #FF7F00).

Why is my result negative or showing as a dash?

Negative numbers cannot be represented as hex, binary, or octal in standard notation. Enter only non-negative values, or use decimal mode for negative number arithmetic first.