Roman Numeral Converter

This tool performs bidirectional conversion between Roman numerals and Arabic numbers. It accepts Roman strings and yields Arabic integers, and accepts Arabic integers and yields Roman strings. The supported range is 1 to 3999. It validates inputs and returns deterministic results, suitable for developers, educators, historians, and data scientists working with historical data, educational materials, or preprocessing pipelines.
Conceptually, Roman-to-Arabic conversion uses a symbol-to-value map and a left-to-right parse with subtractive notation (I before V/X, X before L/C, C before D/M). Arabic-to-Roman uses a greedy decomposition against a ordered numeral list to produce the shortest valid form in uppercase. Both modes are deterministic and avoid ambiguity in edge cases.
Users gain accuracy, speed, and workflow compatibility. Typical use cases include parsing legacy datasets, generating Roman labels for documents, educational exercises, and validating manually derived values in software or databases. The tool provides strict outputs and explicit error signals, enabling reliable integration into scripts and data pipelines without a user interface dependency.
Core capabilities include mode selection, range enforcement, input sanitization, and consistent formatting. Advanced users may adjust validation strictness or extend workflows via API. The design emphasizes reliability, clear error feedback, and compatibility with standard Roman numeral rules used across education, documentation, and historical data representations.