Date October 22nd, 2007 Converted to Roman Numerals

Convert and write the date October 22nd, 2007, i.e. birthday, in Roman numerals

The Roman numerals we are going to use to make the conversion:


I = 1; V = 5; X = 10; M = 1000;

» Roman numerals: basic reading rules

How do we proceed?

Convert, one by one, the numbers that represent the month, the day and the year, to Roman numerals. If the case, break down each number into place value subgroups.


Month, October:

October is the tenth (10th) month of the year.


Replace the name of the month with the corresponding number of the month of the year: 10.


10 = X;


Day, 22:

I = 1; X = 10;

22 = 20 + 2;


20 = 10 + 10 = X + X = XX;


2 = 1 + 1 = I + I = II;


22 = 20 + 2 = XX + II = XXII;


» 22 = XXII


Year, 2007:

I = 1; V = 5; M = 1000;

2007 = 2,000 + 7;


2,000 = 1,000 + 1,000 = M + M = MM;


7 = 5 + 1 + 1 = V + I + I = VII;


2007 = 2,000 + 7 = MM + VII = MMVII;


» 2007 = MMVII


Convert calendar dates, write them in Roman numerals

The set of Roman numerals used for writing calendar dates

  • I = 1 (one); V = 5 (five);

  • X = 10 (ten); L = 50 (fifty);

  • C = 100 (one hundred);

  • D = 500 (five hundred);

  • M = 1,000 (one thousand);

    • For writing dates in the future:
    • (*) V = 5,000 or |V| = 5,000 (five thousand); see below why we prefer: (V) = 5,000.

    • (*) X = 10,000 or |X| = 10,000 (ten thousand); see below why we prefer: (X) = 10,000.

Note 1: (*) These numbers were written either with an overline (a bar above the number) or between two vertical lines (two vertical bars).

Note 2 (*) Instead we prefer to write these larger numerals between brackets "()" since: 1) when compared to the overline - it is more accessible to computer users; 2) when compared to the vertical line - it avoids any confusion between the vertical line "|" and the Roman numeral "I" (one).

  • So, (V) = 5,000 and (X) = 10,000.

Note 3: (*) Romans were not using right from the beginning numbers larger than 3,999, so they initially had no representation for numbers like:

  • 5,000 = (V), 10,000 = (X), 50,000 = (L), 100,000 = (C), 500,000 = (D), or 1,000,000 = (M).

These larger numerals were added later to the system and various different notations were used for them, not necessarily the ones above.

For a long time, the maximum number that could be written using Roman numerals was:

  • MMMCMXCIX = 3,999. .