Roman Numeral Translation Calculator (2024)

Our converter will also show you detailed working out so you can create your own worked examples!

Here is our Roman numeral translation calculatorwhich will help you to convert roman numerals to decimal and decimal to roman numerals.

Our roman numeral translation calculator will also show you the formula and working out you need to convert between the two systems.

This convert will convert numbers up to six digits into Roman numerals.

Roman numeral translation calculator: How It Works...

Step 1) Choose which calculator you want - roman to decimal or decimal to roman

Step 2) Type in the number you want to convert.

Step 3) Click the Convert button and the answer will be displayed.

There are just 7 Roman numerals: I, V, X, L, C, D and M.

Unlike most other number systems, the numerals can only be used in particular sequences.

Another rule is that apart from M, you can only have a maximum of 3 of any given numeral in a row.

Here is a quick overview of the 7 Roman numerals and what each is worth.

We can also use an overline with each Roman numeral which has the effect of multiplying the value by 1000, so:

So XLMM would represent 42,000.

This quick conversion table shows you some common roman number to decimal number conversions.

We have some more detailed Roman Numeral Lists, including printable sets below.

• Roman Numerals Lists

How to convert from Roman to decimal

To convert a Roman number to the decimal (base-10) number system,we need to group the Roman numerals into their values and then add them together.

One thing to remember when doing Roman numeral translation is that the Roman numbers usually go from bigger to smaller.

However, if a smaller value Roman numeral (I, X or C) comes before a larger value then it is subtracted from the larger numeral.

This gives us two simple rules for roman numeral translation:

• When a smaller value numeral comes AFTER a larger value numeral it is ADDED
• But if a smaller value numeral comes BEFORE a larger value numeral it is SUBTRACTED!

An example is that C has the value 100 and X has the value 10.

• CX is worth 100 + 10 = 110, BUT
• XC is worth 100 - 10 = 90 because the X comes before the C.

Example 1) What is XXIV as a number?

Step 1) Split up the Roman numerals into their values.

XXIV = X X IV

The IV has been written as one value because the I comes before the larger value V.

Step 2) Write down the values of each part.

X X IV = 10 + 10 + 4

Step 3) Add them up.

10 + 10 + 4 = 24

So XXIV is equal to 24 as a number.

Example 2) Write CDLXXVI as a number.

Step 1) Split up the Roman numerals into their values.

CDLXXVI = CD L X X V I

The CD has been written as one value because C (100) comes before the larger value D (500).

Step 2) Write down the values of each part.

CD L X X V I = 400 + 50 + 10 + 10 + 5 + 1

Step 3) Add them up.

400 + 50 + 10 + 10 + 5 + 1 = 476

So CDLXXVI is equal to 476 as a number.

Example 3) Write MCMXLVIII as a number.

Step 1) Split up the Roman numerals into their values.

MCMXLVIII = M CM XL V I I I

Step 2) Write down the values of each part.

M CM XL V I I I = 1000 + 900 + 40 + 5 + 1 + 1 + 1

Step 3) Add them up.

1000 + 900 + 40 + 5 + 1 + 1 + 1 = 1948

So MCMXLVIII is equal to 1948 as a number.

How to convert from numbers to Roman Numerals

To convert a decimal number (base-10) to the Roman number system,we need to change the decimal base-10 place value into Roman numerals representing their values.

The chart above can help to do this, or you can try your own worked examples below, on our Roman Numeral Translation calculator above.

Example 1) Convert 64 into Roman numerals.

Step 1) Look at what place values we have.

64 = 60 + 4

Step 2) Write each place value as Roman numerals.

• 60 is LX
• 4 is IV

Step 3) Put the numerals together.

So 64 = LX + IV or LXIV

So 64 is equal to LXIV in Roman numerals.

Example 2) Convert 397 into Roman numerals.

Step 1) Look at what place values we have.

397 = 300 + 90 + 7

Step 2) Write each place value as Roman numerals.

• 300 is CCC
• 90 is XC
• 7 is VII

Step 3) Put the numerals together.

So 397 = CCC + XC + VII or CCCXCVII

So 397 is equal to CCCXCVII in Roman numerals.

Example 3) Convert 3489 into Roman numerals.

Step 1) Look at what place values we have.

3489 = 3000 + 400 + 80 + 9

Step 2) Write each place value as Roman numerals.

• 3000 is MMM
• 400 is CD
• 80 is LXXX
• 9 is IX

Step 3) Put the numerals together.

So 3489 = MMM + CD + LXXX + IX or MMMCDLXXXIX

So 3489 is equal to MMMCDLXXXIX in Roman numerals.

Our Roman Numeral lists can help you to quickly convert different numbers from Roman numerals to numbers.

The lists can also help you to spot patterns and understand how Roman numerals work.

We have a wide range of lists to help you with your Roman numeral conversion.

• Roman Numerals List

We also have a collection of Roman numerals worksheets for helping to learn how to convert from Roman numerals to numbers.

Our worksheets cater for a range of abilites and have differing levels of support.

• Roman Numerals worksheets

Our number system converters will convert numbers from binary, octal or hexadecimal into decimal (or from decimal to binary, octal or hex).

The calculators also show you detailed working out so you can see how to do it yourself!

• Online Binary-Decimal Converter

• Convert Octal to Decimal

• Hexadecimal to Decimal Converter

Our prime number calculator will help you to find all the factors of any given number and tell you whether or not the numberyou are looking at is prime or not.

The calculator will also show you your number as a product of primes.

• Prime Number Calculators

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