Roman Numeral Calculator

Perform arithmetic operations with Roman numerals. Add, subtract, multiply, and divide Roman numerals easily.

Add, subtract, multiply and divide Roman numerals. Get answers in Roman numerals and regular numbers with step-by-step solutions.

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Enter Roman numerals (I-MMMCMXCIX) or Arabic numbers (1-3999)

Try:

Quick Reference

help_outlineHow to Useexpand_more
  1. Select the operation (+, −, ×, ÷)
  2. Enter the first Roman numeral or number (1-3999)
  3. Enter the second Roman numeral or number
  4. Click "Calculate" to see the result

Note:

Your answer may contain Roman numerals with an overline. An overline means the value is multiplied by 1,000 (e.g., V̅ = 5,000).

infoWhat is Roman Numeral Calculator?expand_more

Add, subtract, multiply and divide Roman numerals from I to MMMCMXCIX and/or numbers from 1 to 3999. Get answers in Roman numerals and regular numbers with step-by-step solutions.

Roman Numeral Notation

Roman numerals use additive notation and subtractive notation:

  • Additive: VIII = V + I + I + I = 5 + 1 + 1 + 1 = 8
  • Subtractive: XC = C − X = 100 − 10 = 90

Subtractive notation places a smaller value before a larger one to indicate subtraction, making numerals shorter and easier to read.

functionsFormulaexpand_more

Standard Roman Numerals:

I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1,000

With Overline (×1,000):

V̅ = 5,000
X̅ = 10,000
L̅ = 50,000
C̅ = 100,000
D̅ = 500,000
M̅ = 1,000,000

Subtractive vs Additive Notation:

4 = IV (not IIII)
9 = IX (not VIIII)
40 = XL (not XXXX)
90 = XC (not LXXXX)
400 = CD (not CCCC)
900 = CM (not DCCCC)
lightbulbExamplesexpand_more

Addition

XIV + VII = XXI

14 + 7 = 21

Subtraction

L − XX = XXX

50 − 20 = 30

Multiplication

XII × III = XXXVI

12 × 3 = 36

Division

C ÷ V = XX

100 ÷ 5 = 20

Large result with overline:

MMM × II = V̅I

3000 × 2 = 6000

quizFAQexpand_more
Can I enter regular numbers instead of Roman numerals?expand_more
Yes! You can enter either Roman numerals (like XIV) or regular Arabic numbers (like 14). The calculator accepts both and will show results in both formats.
Why can't I get negative results?expand_more
Roman numerals don't have a symbol for zero or negative numbers. They were developed for counting and practical purposes where negative values weren't needed. If your subtraction would result in zero or a negative number, the calculator will show an error.
What's the largest number I can calculate?expand_more
Input values must be between 1 and 3999 (I to MMMCMXCIX). However, results from multiplication can exceed 3999 and will be shown with overlines (e.g., V̅ = 5,000).
How does division work with Roman numerals?expand_more
Division gives the integer quotient (whole number result). For example, XVII ÷ V = III (17 ÷ 5 = 3 with remainder 2). The calculator shows the remainder when the division isn't exact.
What does an overline mean?expand_more
An overline over a Roman numeral means its value is multiplied by 1,000. For example, V̅ = 5,000, X̅ = 10,000, and M̅ = 1,000,000. This allows representation of numbers larger than 3,999.