Pocket Calculator for Roman Numerals and Decimal Integers. Side-by-side displays simultaneously show your numbers in both Roman numeral and decimal form. This allows easy Roman numeral conversion whilst you perform basic arithmetic operations (add, subtract, multiple, divide).

Numbers can be entered using a conventional decimal keyboard or a Roman numeral keyboard. By choosing the Roman numeral keyboard you can perform Roman numeral calculations and receive the results in Roman numeral or decimal form.

Alternatively if you choose the decimal keyboard, you can perform conventional decimal calculations, and see the results in decimal and Roman numeral form.

Supports all Roman numeral digits I to M, allowing numbers up to 3999 (MMMCMXCIX).

So download the Roman Numeral Calculator now, to effortlessly convert and calculate Roman numerals!

Having trouble reading and old stone inscription, or even understanding that Super Bowl designation? Simply use the Roman Numeral Calculator to convert the numbers into modern decimals, or modify and update them with new Roman numerals.

The Roman Numeral Calculator also has the ability to copy a calculated value to the clipboard. Touch & hold on the display (decimal or Roman Numeral) that you wish to copy the value from. A pop-up menu will appear. Select "Copy Value" to copy the last calculated value from this display to the Android clipboard. This works for both the Roman and decimal keyboards.

This app was originally inspired by Claude Shannon who built a physical calculator that worked with Roman numerals. The 'father of Information Theory', merely created it for intellectual curiosity.

Calculations are limited to the natural numbers (positive integers) and do not support decimal fractions or negative numbers as the Romans were not aware of these in the same sense as us.