New Design Not working For You?

If the new page layout is not working for you, please Contact Me and let me know what device, operating system, and web browser (with version numbers) you are using so I can attempt to get the layout working for your setup.

About the Redesign

If you visited this site prior to September 15th, 2018, you've no doubt noticed that I've since launched a complete redesign of the website.

If you're not happy with the new design, I sincerely apologize. I would have preferred to keep the old desktop design, but considering the majority of my site's users are now accessing the site from small-screen, touch-enabled, mobile devices, and considering Google is now penalizing websites for not being mobile/thumb friendly, I was left with no choice but to switch to a responsive, mobile-first design.

The good news is that now that I have combined the three separate versions of the site (mobile, desktop, and ad-free member) into a single design, this will free up a ton of my time for working to make the mobile-optimized calculators more desktop/laptop friendly. In fact, some of the redesigned calculators already offer a desktop-optimized form that becomes visible when you increase the width setting of the calculator (within the "Calculator Preferences" expandable panel).

Thank you in advance for your help and patience as I work to improve the redesign.


Calculator Preferences
Roman Numeral Converter Sign

Roman Numeral Converter

This online conversion calculator will instantly convert Roman numerals into Arabic numbers, or an Arabic number to a Roman numeral -- and show its work. Includes: invalid entry reporting, a popup keypad for each entry type, and a customizable, printable Roman numeral chart. The Learn tab includes:

  • Roman numeral place-value chart.
  • How to read Roman numerals.
  • How to write Roman numerals.
Learn More

Selected Data Record:

A Data Record is a set of calculator entries that are stored in your web browser's Local Storage. If a Data Record is currently selected in the "Data" tab, this line will list the name you gave to that data record. If no data record is selected, or you have no entries stored for this calculator, the line will display "None".

DataData recordData recordSelected data record: None
Arabic number keypad
Arabic Number Keypad
The following will be entered into the underlying field automatically as you tap the keys.
Roman numeral keypad
Roman Numeral Keyboard
The following will be entered into the underlying field automatically as you tap the keys.

Arabic number or Roman numeral:

Enter either an Arabic number or a Roman numeral (leave no spaces before, within, or after numbers or numerals). For easier entry, tap the plus (+) icon to open the appropriate keypad.

Please note that the Roman numeral converter currently only accepts Arabic numbers up to 3999, and Roman numerals up to MMMCMXCIX.



This is the Arabic number or Roman numeral translation -- depending on which type you entered in the top of the Roman Numeral Converter.

If you would like to save the current entries to the secure database, tap or click on the Data tab, select "New Data Record", give the data record a name, then tap or click the Save button. To save changes to previously saved entries, simply tap the Save button. Please select and "Clear" any data records you no longer need.

Create Conversion Chart

Roman numeral conversion chart:

If you would like to print out a Roman numerals chart, enter the starting Arabic whole number in the From field and the ending Arabic whole number in the To field, and then click the Roman Numeral Chart button. This will open a new, printer friendly window displaying your custom Roman Numeral Chart. Note that the chart will be five columns wide, so try to enter spans that are divisible 5 (1-20, 1-100, 101-200, etc.).

From number:From number:From whole number:From whole number:

Starting number:

Enter the whole number you want the chart to start with.

To number:To number:To whole number:To whole number:

Ending number:

Enter the whole number you want the chart to stop at.

Feedback AppreciatedFeedback Greatly AppreciatedYour Feedback Would Be Greatly AppreciatedYour Feedback Is Greatly Appreciated


Help and Tools

Help and Tools:

This section, which you can Unstick or Hide in the Calculator Preferences (just above the top of the calculator), contains the following tabs (content too long to fit within bordered frame can be scrolled up and down):

About: Click this tab for an introduction to the calculator.

Instructions: Click this tab for step-by-step instructions for using the calculator.

Terms: Click this tab for a list of the descriptions that are located within each popup help button (info icons).

PCalc: Click this tab for a handy "pocket" calculator you can use when you need to calculate an entry needed for the calculator.

Data: Click this tab to save a set of entries or a note in between visits. Entries and notes will be stored to your web browser's local storage (if supported by your browser of choice), meaning they can only be recalled with the same device and web browser you were using when you saved them. If you'd like to save entries and notes between devices you can do so by subscribing to the Ad-Free Member Version.



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