Roman Numerals Calculator — Add, Subtract, Multiply & Divide

Perform arithmetic operations with Roman numerals. Enter two Roman numeral values, select an operation, and get the result in both Roman and Arabic format. Our calculator provides Roman numerals to Arabic numbers translation for better understanding. See also our Roman Numeral Converter and Date to Roman Numerals.

Roman Numerals Calculator

Enter the value that you want to calculate roman numeral.

1st Roman Numeral

Operator

2nd Roman Numeral

Quick Roman ↔ Decimal Converter

Decimal → Roman

Roman → Decimal

Online Roman Numerals Calculator:

Our online roman numerals calculator provides you with addition, subtraction, multiplication, and division of roman numerals. Our roman numerals calculator provides you roman numerals to Arabic numbers translation for better understanding.

About Roman Numerals:

Roman Empire is well known for their intelligence and development — they developed a numeral system for easy business trading. Roman numerals system are standard numbering system used in roman. It is originated from ancient Rome and used the Latin alphabet to represent numbers.

It has seven letters namely I, V, X, L, C, D, and M.
In between 800 to 900 BC firstly this numbering system was used.
Each letter has its own value: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000.
All numbers are formed by using these letters with specific rules.
If a lower value letter placed before a higher value letter then it would be subtracted. For example, 4 is represented as "IV" — "I" is written before "V" so we subtract I from V.
You cannot use the same letter more than three times. For example, CCC = 300 but CCCC is not valid — 400 is written as CD.
You cannot subtract a number that is 10 times higher. For example, 99 = XCIX but you cannot write IC.
The maximum number formed by I, V, X, L, C, D, and M is 3999 (MMMCMXCIX).

How to use roman numerals calculator?

Open Roman Numerals Calculator.
Enter 1st and 2nd roman numerals in their appropriate fields.
Select the operator: addition, subtract, divide, or multiply to perform.
Click on Calculate to get the result.
The result shows in both Roman numeral and Arabic (decimal) format.

Roman Numerals Arithmetic Formula

Roman Numeral Values:
  I = 1    V = 5    X = 10   L = 50
  C = 100  D = 500  M = 1000

Subtractive Combinations:
  IV = 4   IX = 9   XL = 40  XC = 90
  CD = 400 CM = 900

Arithmetic Process:
  Step 1: Convert Roman → Decimal
  Step 2: Perform operation (+, -, ×, ÷)
  Step 3: Convert result Decimal → Roman

Examples:
  XIV + III = 14 + 3 = 17 = XVII
  L - XX = 50 - 20 = 30 = XXX
  VII × IV = 7 × 4 = 28 = XXVIII
  C ÷ V = 100 ÷ 5 = 20 = XX
  MCMXCIX + I = 1999 + 1 = 2000 = MM

Roman Numerals 1 to 100 Chart

Number	Roman	Number	Roman	Number	Roman	Number	Roman
1	I	26	XXVI	51	LI	76	LXXVI
2	II	27	XXVII	52	LII	77	LXXVII
3	III	28	XXVIII	53	LIII	78	LXXVIII
4	IV	29	XXIX	54	LIV	79	LXXIX
5	V	30	XXX	55	LV	80	LXXX
6	VI	31	XXXI	56	LVI	81	LXXXI
7	VII	32	XXXII	57	LVII	82	LXXXII
8	VIII	33	XXXIII	58	LVIII	83	LXXXIII
9	IX	34	XXXIV	59	LIX	84	LXXXIV
10	X	35	XXXV	60	LX	85	LXXXV
11	XI	36	XXXVI	61	LXI	86	LXXXVI
12	XII	37	XXXVII	62	LXII	87	LXXXVII
13	XIII	38	XXXVIII	63	LXIII	88	LXXXVIII
14	XIV	39	XXXIX	64	LXIV	89	LXXXIX
15	XV	40	XL	65	LXV	90	XC
16	XVI	41	XLI	66	LXVI	91	XCI
17	XVII	42	XLII	67	LXVII	92	XCII
18	XVIII	43	XLIII	68	LXVIII	93	XCIII
19	XIX	44	XLIV	69	LXIX	94	XCIV
20	XX	45	XLV	70	LXX	95	XCV
21	XXI	46	XLVI	71	LXXI	96	XCVI
22	XXII	47	XLVII	72	LXXII	97	XCVII
23	XXIII	48	XLVIII	73	LXXIII	98	XCVIII
24	XXIV	49	XLIX	74	LXXIV	99	XCIX
25	XXV	50	L	75	LXXV	100	C

Frequently Asked Questions

How do you add Roman numerals?

Convert both Roman numerals to decimal numbers, add them, then convert the sum back to Roman numerals. Example: XIV + III = 14 + 3 = 17 = XVII.

What is the maximum Roman numeral?

Using standard notation, the maximum is MMMCMXCIX = 3999. To write higher numbers, an overline is used to multiply by 1000 (e.g., V̅ = 5000).

Can you multiply Roman numerals?

Yes. Convert to decimal, multiply, then convert back. Example: VII × IV = 7 × 4 = 28 = XXVIII. The result must be between 1 and 3999.

What are the 7 Roman numeral symbols?

I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). All Roman numerals are formed by combining these seven symbols.

Why can't you repeat a letter more than 3 times?

This rule keeps numbers compact using subtractive notation. Instead of IIII for 4, write IV (5-1). Instead of CCCC for 400, write CD (500-100).

Objective of Measurement:

Measurement is the most important aspect of our life. We use measurement in science, engineering, business trading, personal life, education, and more other fields. As technology is growing day by day so we need a highly accurate and easy convenient global measuring system in each and every field. It is essential to use standard measurement in every field that everyone to be sure that they not get cheated.

History of Measurement:

In history for measurement people used the human body as a tool. For measuring length used forearm, hand, foot & finger as a unit. The foot, finger is a subdivided shorter unit of a length. This type of measurement is not accurate cause different in size of the arm & finger for different people & some of the countries still using it. In history, there were lots of measuring systems developed but mostly used imperial, the metric system of measurement. We use these systems for measure distances, volume, weight, speed, area etc. Due to this a major problem everyone is facing while doing trading between the countries. A huge improvement in civilization, It necessary to improve measuring standards. Nowadays International Standard (SI) units are used as a global measurement system.

Solved Examples

Example 1: Calculate XLVII + XXIX

Step 1: Convert to decimal — XLVII = 40+5+1+1 = 47, XXIX = 10+10+9 = 29.

Step 2: Add — 47 + 29 = 76.

Step 3: Convert back — 76 = 50+10+10+5+1 = LXXVI.

Answer: XLVII + XXIX = LXXVI (76)

Example 2: Subtract MCMXCIX − MDCCCXCIX

Step 1: MCMXCIX = 1999, MDCCCXCIX = 1899.

Step 2: 1999 − 1899 = 100.

Step 3: 100 = C.

Answer: MCMXCIX − MDCCCXCIX = C (100)

Example 3: Multiply XII × VII

Step 1: XII = 12, VII = 7.

Step 2: 12 × 7 = 84.

Step 3: 84 = 50+10+10+10+4 = LXXXIV.

Answer: XII × VII = LXXXIV (84)

Example 4: A building cornerstone reads MCMLXVIII. What year was it built?

Step 1: Break down — M=1000, CM=900, LX=60, VIII=8.

Step 2: Sum — 1000 + 900 + 60 + 8 = 1968.

Answer: The building was constructed in 1968.

Practice Questions

Calculate XIV + XXVIII and express the result in Roman numerals. (Answer: XLII = 42)
What is C − XXXVII in Roman numerals? (Answer: LXIII = 63)
Multiply IX × IX. (Answer: LXXXI = 81)
Divide CXLIV ÷ XII. (Answer: XII = 12)
The Super Bowl in 2020 was numbered LIV. What number is that? (Answer: 54)
A movie credits show MMIII. What year was it produced? (Answer: 2003)

Common Mistakes to Avoid

The most frequent error with Roman numeral arithmetic is misreading subtractive notation. Remember that IV means 4 (not 6) and IX means 9 (not 11) — whenever a smaller-value symbol appears before a larger one, subtract it. Another common mistake is writing invalid combinations like IC for 99 (the correct form is XCIX) or VL for 45 (correct: XLV). The subtraction rule only applies to specific pairs: I before V or X, X before L or C, and C before D or M. You cannot subtract across more than one level. Students also sometimes repeat symbols more than three times (IIII instead of IV, XXXX instead of XL). When performing arithmetic, always convert to decimal first, perform the operation, then convert back — attempting to add or subtract Roman numerals directly without conversion leads to errors because the system is not purely positional.

Key Takeaways

Roman numerals use seven symbols: I(1), V(5), X(10), L(50), C(100), D(500), M(1000).
Subtractive notation: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900.
The valid range is 1 to 3999 (MMMCMXCIX) in standard notation.
For arithmetic: convert to decimal → perform operation → convert result back to Roman.
Never repeat a symbol more than three times — use subtractive pairs instead.
Roman numerals are still used today: clock faces, Super Bowl numbering, movie dates, building cornerstones, outlines, and royal/papal names (Queen Elizabeth II, Pope John Paul II).

Related Calculators:

Roman Numeral Converter Date to Roman Numerals Number to Words Base Converter Binary Calculator Number Converter