Hex to Decimal Converter

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Hex ↔ Decimal Quick Reference

HexDecimal
00
11
22
33
44
55
66
77
88
99
A10
B11
C12

How to Convert Hex to Decimal

A hexadecimal number is read right to left, and each digit is worth 16 times more than the digit to its right. To convert to decimal, multiply each digit by its place value and add the results:

  • The rightmost digit is worth ×1 (16⁰)
  • The next is worth ×16 (16¹)
  • Then ×256 (16²), ×4096 (16³), and so on

The letters A–F stand for the values 10–15 — hexadecimal needs sixteen distinct digits, and the alphabet supplies the six that 0–9 cannot.

Step-by-Step Example

Convert 1A3 to decimal:

  1. Write out the place values: 1 is in the 256s place, A in the 16s place, 3 in the 1s place
  2. Multiply: 1 × 256 = 256, then A (= 10) × 16 = 160, then 3 × 1 = 3
  3. Add them: 256 + 160 + 3 = 419

So 1A3 in hex is 419 in decimal. The same method works for any length — a fourth digit is multiplied by 4096, a fifth by 65,536.

Where Hex Numbers Come From

You will meet hexadecimal any time software shows you raw values, because one hex digit is exactly four bits and two hex digits are exactly one byte:

  • Error codes — a Windows stop code like 0x8007045D is a hex number; converting it to decimal is often the first step in looking it up.
  • Color codes — in #FF6600, each pair is one channel: FF is 255 red, 66 is 102 green, 00 is no blue.
  • Memory addresses and file offsets — debuggers and hex editors display positions in hex.
  • MAC addresses and device IDs — hardware identifiers are written as hex pairs.

Three Things That Trip People Up

  • The 0x prefix is not part of the number. 0x1A3 and 1A3 are the same value — the prefix only announces "what follows is hex". This converter accepts it either way.
  • Case does not matter. 1a3 and 1A3 are identical. Uppercase is just the common display convention.
  • A hex number can look decimal. The string 100 is one hundred in decimal but 256 when read as hex. When a number arrives without context, check which base it is in before trusting it — this is the single most common conversion mistake.

Frequently Asked Questions

What is FF in decimal?

FF in hexadecimal is 255 in decimal: F stands for 15, so FF is 15 × 16 + 15 = 255. It is the largest value one byte can hold, which is why 255 appears as a limit throughout computing.

How do I convert hex to decimal by hand?

Multiply each hex digit by its place value — 1 for the rightmost digit, 16 for the next, then 256, then 4096 — and add the results. The letters A through F count as 10 through 15.

Do I include the 0x when converting?

No. The 0x prefix only marks the number as hexadecimal; it has no value itself. 0x1A3 and 1A3 are the same number, and this converter accepts both.

Does uppercase or lowercase matter in hex?

No — 1a3 and 1A3 are exactly the same value. Uppercase is the usual display convention, and this converter shows results in uppercase.

Going the other way? Use the Decimal to Hex Converter.