Hexadecimal (Base 16) to Decimal (Base 10) Converter
Convert hexadecimal numbers to decimal.
FF (base 16) = 255 (base 10)
Digits in base 16: 0 to 9 and A to F. Digits in base 10: 0 to 9.
How to convert Hexadecimal to Decimal
Every positional number system works the same way: a digit is worth its own value times the base raised to the power of its position. In base 16 the place values, from the right, are 160 = 1, 161 = 16, 162 = 256 and so on.
To get from base 16 to decimal, multiply each digit by 16 raised to the power of its position, counting from 0 on the right, and add the results.
The method
decimal value = each digit × its place value, all added upplace values in base 16: 1, 16, 256, 4096, 65536, and so ondigits in base 16: 0 to 9 and A to Fdigits in base 10: 0 to 9
Worked example 1: 2D from hexadecimal to decimal
2D (base 16) = 2 × 161 + 13 × 160= 32 + 13= 452D (base 16) = 45 (base 10)
Letters stand for values from 10 up: A = 10, B = 11, C = 12 and so on. Digits that are 0 add nothing to the sum, so they are left out of the expansion.
Worked example 2: FF from hexadecimal to decimal
FF (base 16) = 15 × 161 + 15 × 160= 240 + 15= 255FF (base 16) = 255 (base 10)
Worked example 3: 3E8 from hexadecimal to decimal
3E8 (base 16) = 3 × 162 + 14 × 161 + 8 × 160= 768 + 224 + 8= 1,0003E8 (base 16) = 1000 (base 10)
Need the other direction? Open the Decimal to Hexadecimal converter.
Hexadecimal to Decimal examples
The decimal number 255 is written FF in hexadecimal and 255 in decimal.
| Hexadecimal | Decimal |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 7 | 7 |
| 8 | 8 |
| A | 10 |
| F | 15 |
| 10 | 16 |
| 20 | 32 |
| 40 | 64 |
| 64 | 100 |
| FF | 255 |
| 3E8 | 1000 |
Where Hexadecimal to Decimal comes up
Hexadecimal (base 16) uses 0 to 9 and A to F, and each hex digit stands for exactly four bits, so one byte is always two hex digits. You see it in web colours like #FF8800, memory addresses, MAC addresses, hash values and byte dumps.
Decimal is the base 10 system everyone learns first, with the digits 0 to 9. It is the form people read: prices, measurements, ages and IDs. It is also the base we calculate in by hand, which is why the worked steps on this page pass through decimal.
Going to a smaller base spreads the same value over more digits, so the result is longer. The number 255 needs 2 digits in hexadecimal and 3 in decimal.
Hexadecimal to Decimal FAQ
How do I convert hexadecimal to decimal?
Multiply each base 16 digit by 16 raised to the power of its position, counting from 0 on the right, then add everything up.
Which digits does hexadecimal use?
Base 16 uses the digits 0 to 9 and A to F. For example, G is not a valid digit in base 16. Letters are not case sensitive on this converter, and results are shown in capitals.
Will the decimal number be longer or shorter?
Longer. Going to a smaller base spreads the same value over more digits, so the result is longer. Roughly 1.2 decimal digits for every hexadecimal digit. The number 255 needs 2 digits in hexadecimal and 3 in decimal.
What is FF in decimal?
FF in hexadecimal is 255 in decimal. Both are the decimal number 255.
Can I convert negative numbers or fractions?
The converter handles whole numbers, and a leading minus sign works for negatives. Fractions use a different method, where you repeatedly multiply the fractional part by the new base, and they are not supported here.