Emulates classic Hewlett Packard RPN scientific calculators from the 1970s. Experience the original HP-35, HP-45, and HP-21 models on your iPhone.
2.6
March 22, 2026
Minor Improvements and bug fixes
HP-35 emulates the classic Hewlett Packard HP-35, HP-45, and HP-21 RPN calculators. These were among the first pocket scientific calculators released in the 1970s.
Yes, HP-35 is completely free to download and use. It does not require any payment or in-app purchases.
HP-35 is currently supported on iPhone devices. It is designed for the iOS mobile operating system.
The latest version, 2.6, was released on March 22, 2026. While the last update date is in the future, indicating ongoing development, users can expect updates to maintain compatibility and potentially add features.
HP-35 has an excellent rating of 5.0 stars based on 5 user reviews. This indicates a very high level of user satisfaction.
No, HP-35 does not contain advertisements. Users can enjoy an ad-free experience while using the calculator.
Reverse Polish Notation (RPN) is a mathematical notation where every operator follows all of its operands. This differs from the more common algebraic notation and is a key feature of the emulated HP calculators.
HP-35 has an age rating of 4+. This means it is suitable for users of all ages, with no content restrictions.
