People are still fascinated by Roman numerals. Invented more than 2000 years ago, they are still used in many places today. Although they are not very good for arithmetic, they are great when the numbers are simply used for counting.

You find them used to show the year when a building was built, a film was made or a book was published. The BBC website uses them for the copyright date on all its pages. They are also used on the pages of books before the main part starts or to show subheadings. And sports events are often designated by a Roman numeral. The Beijing Olympics in 2008, the 29th games in modern times, were the Games of the XXIX Olympiad and London's Games in 2012 will be the XXX Olympic Summer Games. In fact, the International Olympic Committee seems to be moving away from using Roman numerals. In the USA the American Football championship is called Super Bowl. In 2009, the 43rd championship was Super Bowl XLIII and in 2010 it is Super Bowl XLIV.

If you are puzzled already about why 29 is written XXIX and 44 is written XLIV then you need these pages!

Here you will find a general guide to how Roman numerals work and their history. They enable you to convert numbers to Roman and to convert Roman numerals back to our system. They also answer those tricky questions about 1999, about clock faces, and about how the Romans wrote really big numbers like a million. And of course what did Romans use for zero?

These pages also contain information about the Roman calendar. The calendar used today in most of the world is based on the system devised by the Roman Emperor Julius Caesar and perfected by Augustus Ceasar. But the way the Romans counted days and described dates was very different, even though the calendar was essentially the same. These pages explain the history and use of the calendar and how to translate dates into - and out of - Roman.

I get many emails about Roman numerals and dates and I am happy to answer them, but give me a few days. And please read these pages thoroughly first. The answers to most questions about Roman numerals and dates which I can answer, are somewhere in these pages. I don't know much about Latin and very little about Roman history, so I won't normally be able to answer questions about either of those topics.

There are lots of other pages on the internet about Roman numerals and calendars. Some of them are listed in these pages. But a Google search is usually the best way to find them. You can also read about Roman numerals and calendars in books. The calendar pages have a short bibliography

If you have used these pages, please tell me what you used them for, whether they answered your question, and what else you would like to see. 

All material on these pages is Paul Lewis 1996-2010