PCalc is the powerful choice for scientists, engineers, students, programmers, or indeed anybody looking for a feature rich calculator. It includes an optional RPN mode and multi-line display, a choice of button layouts, an extensive set of unit conversions and constants, a paper tape, multiple undo and redo, engineering and scientific notation, as well as support for hexadecimal, octal, and binary calculations.PCalc Lite is a fully functional and free taste of our very popular scientific calculator. It includes an optional RPN mode, multiple undo and redo, unit conversions and constants, as well as two stylish themes and our highly praised design. A great choice for your new iPad!

If you like what you see, the full version has many more settings and themes, a paper tape, engineering and scientific notation, and full support for hexadecimal, octal, and binary calculations. You can also now purchase extra features directly from inside PCalc Lite. Buy them individually, or buy everything.

Includes an Apple Watch app, so you can calculate on your wrist!

What's New

Version 3.7.6

Added support for measuring angles with grads in trigonometry functions.
Added a button to erase all settings and iCloud data.
Fixed a problem searching for units in the conversion section.
Fixed a problem pasting values with a unicode minus sign.

With the "Theme Pack" installed:
Added a new theme, "Dark Night".

With the "Engineer Pack" or "Programmer Pack" installed:
Added a "Percentage Total" (%T) button to the layout editor.

With the "Power User Pack" installed:
Added an option to display SI prefixes in Engineering display mode.
Renamed "Use Constant Functions" to the more obvious "Repeat Operation on Equals".

Ratings and Reviews

4.5 out of 5

61 Ratings

61 Ratings

Highly recommended

Reluctant Lemming

I Purchased PCalc and was immediately impressed. Honestly, this app has no peer. Fully customizable, with deep and thorough functionality, it’s hard to imagine anything could be better. After trying the Lite version I jumped and purchase the additional packs and never looked back. Also, I had reason to contact PCalc with a question and they replied immediately. I was totally impressed. Thank you for a great app PCalc people!

Engineering decimal places


Overall, an excellent calculator app. Will award that 5th star when the Engineering Decimal Places is fixed.

Correct implementation will show the same number of significant digits as specified. The flawed implementation controls only digits after the decimal. Thus the significant digits shown is different depending on value. Very annoying. (See HP for correct approach.)

If this is all that’s wrong, then these folks have produced a top quality product. Hope y’all fix it!

A terrific calculator!


There seems no end to the design wisdom built into this little app. I own several of the add-ons to PCalc Lite and am delighted with the way it functions, including its customizability. Fresh dated currency conversions among numerous other conversions and reverse notation (hp12c style) are just two of the best features, though certainly not close to all! Highly recommended!

Developer Response

If you have purchased the Power User Pack, there is an option in the Advanced settings called Clear on Open. Turning that option off should do the trick. If it doesn't, please send an email to so we try to solve this.


TLA Systems Ltd.
91.9 MB
Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© 1992 - 2018 James Thomson
In-App Purchases
  1. Conversion Pack $0.99
  2. Complete Pack $9.99
  3. Multiple Line Pack $0.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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