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Plus42

Plus42

Enhanced HP-42S Calc Simulator

79 ratings
39 reviews
#73 in paid Utilities
🔧 Utilities
$9.99

Details

Released
April 28, 2022
Updated
November 5, 2026

Features

Developer

Thomas Okken
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ipad
📈no. 73
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About

This advanced scientific calculator simulates the HP-42S RPN calculator with enhanced features. It offers algebraic expressions, unit conversions, directory storage, a resizable display, financial functions, and 2D plotting capabilities.

✓HP-42S RPN calculator simulation
✓Algebraic expressions
✓Attached units and conversions
✓Directory storage for programs/variables
✓Resizable 8-row, 22-column display
✓Time value of money and amortization
✓2D function plotting with zoom and pan
Show original description
+1

What's New in Plus42

1.5.2

November 5, 2026

Implemented ARG. When using LTOP and ATOP options together, to show both the LASTX and ALPHA registers at the top of the stack area, the user can now control the order in which they appear: whichever one was enabled most recently will be above the other. Implemented conversions to and from DPD-encoded decimal floating point: N→PS/PD/PQ, PS/PD/PQ->N. Fixed two-argument STOFLAG. It got broken in 1.5. Fixed pasting of HP-41 style GTO/XEQ IND X/Y/Z/T/L.

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Charts

Top Paid

📈 73+31

Utilities

This app rose +31 positions in Utilities chart.

Last updated on November 10, 2026.

User reviews

Most RecentHighest RatedLowest Rated

Plus42 fanatic simulator

This is a fantastic HP-42S simulator. Very functional, I use it daily. My HP calculator has long been dead and this allows me to use an RPN scientific calculator in daily engineering tasks. Thank you.
KKAPuser

Not worth of it

Don’t waste your money!
AAAbe Aybar

Best calculator app!

I *LOVE* Free42
Plus42 is even better!
ISIT Problem Solver

Perfection

Once you use an RPN calculator, you will never go back. The HP-42S beats the HP Prime in layout and ease of use for most task, and the enhancements in this implementation is great. I love having the (enhanced) HP-42S always with me on my iPhone whenever I need a calculator.
CSCasually Serious

Can’t convert from DMS to decimal degrees!

WTF. It can easily convert decimal degrees to DMS, but not DMS to decimal degrees?!? What is the point of having one but not the other?!?
Ddhuncth

Response from developer

The function to convert degrees/hours, minutes, and seconds to decimal degrees/hours is called →HR. It's in the CONVERT menu, right next to →HMS. Note that I would have noticed your comment much more quickly if you had emailed me. This space is for app reviews, not for tech support.

See 34 more reviews

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FAQ

What is Plus42 based on?

Plus42 is an advanced scientific programmable calculator based on Free42, which is a complete re-implementation of the HP-42S scientific programmable RPN calculator.

What are the key enhancements in Plus42 over Free42?

Plus42 adds algebraic expressions, attached units and unit conversions, directories for storage, a larger resizable display, time value of money functions, and two-dimensional plotting.

What devices does Plus42 support?

Plus42 is available for iPhone, iPad, and iPod.

How much does Plus42 cost?

Plus42 is a paid application priced at $9.99.

What is the age rating for Plus42?

Plus42 has an age rating of 4+, making it suitable for a wide range of users.

How often is Plus42 updated?

The latest version, 1.5.2, was last updated on November 5, 2026. This indicates a recent update, suggesting ongoing support.

What is the user rating for Plus42?

Plus42 has an excellent rating of 4.9 stars based on 79 ratings, indicating high user satisfaction.

Does Plus42 have ads?

No, Plus42 does not contain advertisements, providing an uninterrupted user experience.