Hexadecimal Conversion for large numbers
The following utility will enable you to convert hexadecimal to decimal and vice versa, it's a PHP based version of the standard conversion page, unfortunately it will re-load the page when calculating the answer but the benefit is that now it will convert up to 100 digit numbers. I'm putting this into beta on the 23rd June 2013, please shout via twitter (bottom of page) or Facebook comment if any issues.
Hexadecimal is base 16.
Base 16 is where the 'numbers' you can use are zero through to the letter F (0123456789ABCDEF). i.e. the decimal value for '1' is represented in hexadecimal as '1' but the hexadecimal value of '15' (decimal) is shown as 'F' (hexadecimal) and the value of '17' (decimal) is '11' in Hexadecimal.
| Decimal | Hex | Decimal | Hex | Decimal | Hex |
| 1 | 1 | 11 | B | 30 | 1E |
| 2 | 2 | 12 | C | 40 | 28 |
| 3 | 3 | 13 | D | 50 | 32 |
| 4 | 4 | 14 | E | 60 | 3C |
| 5 | 5 | 15 | F | 70 | 46 |
| 6 | 6 | 16 | 10 | 80 | 50 |
| 7 | 7 | 17 | 11 | 90 | 5A |
| 8 | 8 | 18 | 12 | 100 | 64 |
| 9 | 9 | 19 | 13 | 500 | 1F4 |
| 10 | A | 20 | 14 | 1000 | 3E8 |