Roman Numeral Rules

Roman numerals combine symbols using two rules:

• Additive rule: when symbols are equal or decrease in value from left to right, add them (e.g. VII = 5 + 1 + 1 = 7).
• Subtractive rule: when a smaller symbol comes before a larger one, subtract it (e.g. IV = 5 − 1 = 4).

Apply the additive or subtractive rule to find a value.

Continue exploring related topics:

• Roman Numeral Symbols
• Roman Numerals 1–1000
• Common Roman Numeral Mistakes