Convert numbers to Roman numerals and Roman numerals back to numbers — one box, both directions.
Type a whole number from 1 to 3999 and get the numeral; type a numeral (like MCMLXXXIV) and get the number. Standard subtractive notation is used (4 = IV, 9 = IX, 1994 = MCMXCIV). Roman numerals have no zero and max out at 3,999 in the standard system.
Why only up to 3999? Beyond that, Romans used a bar over a numeral to multiply by 1,000 — notation plain text can’t show reliably, so the standard modern range stops at MMMCMXCIX (3999).
What year is MMXXVI? 2026 — MM (2000) + XX (20) + VI (6).