C47 Web Calculator

C47 Web Calculator is an in-browser implementation of the C47 / R47 RPN scientific calculator firmware, inspired by the Hewlett-Packard HP-42S and the Swiss Micros DM42. It supports 47-digit decimal precision, matrices, statistics, complex numbers, integer modes, programs, and over 600 built-in functions. No accounts, no telemetry, no ads — runs entirely in your browser via WebAssembly and persists state locally. Installable as a Progressive Web App on iPhone, iPad, Android, macOS, Windows, and Linux for full offline use.

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