Hex to Decimal Converter

What does this Hex to Decimal Converter do?

This free online hex to decimal converter turns any base-16 number into its base-10 equivalent. Hexadecimal uses 16 digits: 0 through 9 for values 0–9, and the letters A through F for values 10–15. It's the compact, human-readable shorthand that programmers use for binary data, memory addresses, and color codes.

Beyond just showing you the decimal result, this converter walks through the standard positional expansion step by step. You'll see each hex digit multiplied by its positional power of 16, and how all the products sum to the final decimal value. It also provides the binary and octal equivalents, since these number systems are closely related to hexadecimal.

Everything runs locally in your browser. The number you enter never leaves your device — no server, no logs, no tracking. You can convert as many numbers as you want, with no limits and no signup.

How to convert hexadecimal to decimal

1. Enter a hexadecimal number: Type any hex value (0–9, A–F) into the input field. Both uppercase and lowercase are accepted. You can also include the 0x prefix if you want.
2. Click Convert: The converter instantly computes the decimal equivalent and displays it.
3. Review the breakdown: Below the result, you'll see each hex digit multiplied by its positional power of 16, showing exactly how the decimal value was calculated.
4. Check the alternatives: The binary and octal equivalents are shown alongside the bit count and number of hex digits.
5. Copy if needed: Use the "Copy Results" button to grab a formatted summary.

That's it. No signup, no email, no waiting. The entire process takes seconds.

Hexadecimal to decimal conversion method

The standard method for converting a hexadecimal number to decimal is positional expansion. Each hex digit is multiplied by 16 raised to the power of its position, then all the products are summed.

The key insight is that hex is just a positional number system like decimal, except the base is 16 instead of 10. In decimal, the rightmost digit is multiplied by 10⁰ = 1, the next by 10¹ = 10, then 100, 1000, and so on. In hex, the rightmost digit is multiplied by 16⁰ = 1, the next by 16¹ = 16, then 256, 4096, and so on.

Hex to decimal reference table

Here's a quick reference for common hexadecimal values and their decimal equivalents, along with binary for comparison.

Notice the pattern: values like F, FF, FFFF, and FFFFFFFF are one less than powers of 16 (16¹, 16², 16⁴, 16⁸), and their decimal equivalents are one less than powers of 2 (2⁴−1, 2⁸−1, 2¹⁶−1, 2³²−1). This is why hex is so convenient for representing binary data — every 4 bits maps cleanly to one hex digit.

Where hex-to-decimal conversion is used

Converting hex to decimal is a fundamental skill in computing because hex is how programmers and systems display binary data in a compact form.

Debugging and reverse engineering

When you inspect a crash dump, disassemble a binary, or read a hex editor, addresses and values appear in hexadecimal. Converting them to decimal helps you reason about array indices, buffer sizes, and memory offsets. For example, if a memory address is 0x7FFE1234, converting it to decimal gives you a concrete number you can compare against other addresses.

Color codes in web design

CSS colors like #FF5733 are hex, and each pair of hex digits represents a red, green, or blue channel from 0 to 255. Converting FF to decimal gives you 255 (full intensity), and 80 gives 128 (half intensity). Designers and developers often need the decimal values when working with graphics APIs or color libraries that expect RGB integers.

MAC addresses and IPv6

MAC addresses (like 00:1A:2B:3C:4D:5E) and IPv6 addresses (like 2001:0db8:85a3::8a2e:0370:7334) are written in hex. Converting segments to decimal is sometimes needed for logging, filtering, or computing network ranges.

Character encoding

Unicode code points are written in hex, like U+0041 for 'A' or U+1F600 for 😀. When working with character encodings, you often need the decimal value of a code point to index into character tables or compare against ASCII values.

Cryptography and hashing

Cryptographic hashes and binary protocol fields are commonly displayed in hex. When analyzing a hash or comparing byte sequences, you might convert hex values to decimal to perform arithmetic or compare sizes.

Bitwise programming

Programmers use hex literals like 0xFF for bit masks and flags. Understanding the decimal value (255 for 0xFF) helps when setting register values, defining enums, or reasoning about the numeric range of a bit field.

Why use this converter?

Common mistakes to avoid

• Forgetting that A–F stand for 10–15. Writing A as "1" instead of 10, or F as "15" instead of 15 is fine, but mixing the two up leads to wrong results. Always convert letters to their numeric values before multiplying.
• Starting the power count at 1 instead of 0. The rightmost digit has power 16⁰ = 1, not 16¹. Off-by-one errors in the exponent are the most common mistake.
• Reading the digits in the wrong order. Hex numbers are read left to right, but the positional weights increase from right to left. The leftmost digit has the highest power.
• Assuming all hex numbers are 8 digits. Hex numbers have no fixed width unless you specify one. FF is 2 digits and equals 255, not 65535 (which would be FFFF).
• Mixing up hex and decimal digits above 9. When you see "10" in a hex context, it means 16 in decimal. When you see "10" in a decimal context, it means ten. Context matters.
• Confusing hex with BCD. Hex is a positional base-16 system, while BCD (Binary-Coded Decimal) encodes each decimal digit separately in 4 bits. For example, decimal 12 in hex is C, but in BCD it's 0001 0010.

Frequently asked questions