As part of my series on TSQL Program Chrestomathy, this is a couple of TSQL routines that convert between integers and roman numerals.  There are two functions, one for each direction of conversion. These are a slight revision and expansion of what I published on a blog in 2011. I’ve added a bit more of the original test suite The problem with Roman Numerals is that there is no ANSI Standard for them. Originally, it was a simple tally system which grew rather organically, and was still being developed up to the time (14th Century) that we sighed and adopted hindu-arabic numerals. Even after that point, they were being used for timber construction until the eighteenth century because the marks were easy to make with a chisel. Nowadays, they are used occasionally for floor numbering, in books and documents for paragraph numbering, in some countries for denoting the day of the week, for clock-faces,  and  The subtractive notation was a late arrival, though that and the double-subtractive were used in Roman times. To get some decent-sized numbers, I use the system based on Etruscan usage for large numbers, though I agree that it all goes a bit nebulous after 200000.