there are plenty of online tools that can do it, for example:
http://www.binaryhexconverter.com/he...imal-converter
0x would unambiguously state that the following value is hexadecimal and the number before the x represents a count of 16s before it, so 1x1 is basically 16 + 1, 2x1 is 32 + 1 aka 33, 2xF is 32 + 15 aka 47 etc
whereas if you used the true hexadecimal value for 17 which is '11' that would appear more ambiguous