The R47: A new physical RPN calculator released today in 2025

The next RPN scientific

The R47 is a powerful, RPN-based programmable scientific calculator with an extensive feature set. Its software has been refined over many years, born from the vision of a dream calculator developed by a team of engineers and mathematicians, all dedicated calculator enthusiasts.

Background and lineage

Community-developed and manufactured by SwissMicros, the R47 runs firmware that is functionally identical to that of the C47, which offers a way to transform a DM42n into a feature-rich RPN calculator using a dedicated keypad overlay.

The C47/R47 firmware originated as a fork of the WP43 project, itself derived from the WP34S. A core component carried through this lineage is the decNumber library by Mike Cowlishaw, also used in GCC for precise decimal arithmetic.

Inspired by the HP‑41C and HP‑42S, the R47 builds on this foundation with a redesigned keypad featuring two shift keys, preserving a familiar feel while being entirely new in execution.

R47 calculator features

• Advanced Math Capabilities:
  • Solve equations and systems of equations.
  • Perform definite and indefinite integration.
  • Handle matrix and vector calculations.
  • Work with complex numbers.
  • Utilize base-n arithmetic.
  • Provides 34 digits of precision; exponents to ±6144; up to 1000 named variables.
  • Utilizes scientific calculator functions like trigonometry, hyperbolics, logs, and antilogs.
  • Features a 2-variable statistics with best-fit modelling and basic plotting.
• Programming and Editing:
  • Create programs using a multi-line editor.
  • Keystroke programmable with tests, flags, looping, and branching.
• Engineering and Utilities:
  • Conduct financial and date-based calculations, including time value of money operations.
  • Apply built-in unit conversions and library of constants.
  • Perform date and time math as well as built-in clock.
  • Equation writer with support for solving, numeric integration and derivatives, and basic plotting.
• Display and User Interface:
  • Features a high-resolution display with 4 stack levels, 3 rows of menus, and status bar always shown.
  • User-customizable keyboard and softkey-based menus.
• Data Management:
  • I/O to built-in flash memory or via USB for backing up and restoring states, programs, and configuration.

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The R47 was developed in collaboration with the C47/R47 team. The hardware is provided by SwissMicros, and the software by the C47/R47 team.

For software updates and documentation, please contact the C47/R47 team at https://47calc.com/. I understand that the R47 firmware is not written, distributed, or maintained by SwissMicros, and I agree that any support for the R47 firmware will be requested and handled by the R47 team via email to [email protected]

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Please note: The R47 wil lget dispatched on Monday, November 17th 2025.