12Calc is a full version of the well known HP12C for the iPhone and iPad. It also includes an audit tape, unit converter, worksheets, rotated views, user guide and HD graphics optimized for iPad and iPhone retina displays.

•Runs in 64 bit mode on the latest iOS release and new iPads and iPhones.

•Calculations are highly accurate and blazing fast. No more "running" flashing displays for amortizations, depreciation schedules or interest calculations. Work as fast as you can type.

•Audit Tape: The audit tape keeps a record of your calculations. You can review, mail, text, share or print the tape.

•Unit Converter: Convert between a wide variety of common units and currencies. Currency rates can be downloaded from the internet.

•Work Sheets with interactive graphs:
Auto Purchase
Cash Flow analysis
Interest Conversion
Loan Amortization (includes option for Canadian mortgages)

•Views for all orientations: Portrait and landscape renderings of the full keyboard are provided for iPhone and iPad. The iPad version includes slide over and multiple split view displays as well as side-by-side display of the help page, audit tape, tvm mortgage table or program variables.

•Built-in contextual help: Touch the ? key for a description of any keyboard function with examples of use. If you are just learning or can't remember how to use a function- just touch the ? key. Includes tutorials on how to use reverse Polish notation (RPN) and how to solve time value of money problems.

•HD Graphics: Graphics optimized for both retina and standard resolution screens. Choose from multiple color schemes including gold, rose gold, brass, copper, silver and several color tints.

What's New

Version 2.2

• Update to work around iOS11.0.1 bugs. Apple is changing the view system without working out all the details. Important pieces such as setRightBarItems have just stopped working as a result of introducing a big black notch smack in the middle of the top of the screen. How is this a good idea? My users certainly have let me know they don't appreciate updating iOS and then their apps no longer work.
• To my users- I'm trying to stay on top of this and will continue to update the app to work around Apple's latest "design innovations" :-(
• Restored waste basket and action buttons on audit tape for iPhone
• Added taptic feedback on key touches (requires iPhone with taptic engine)

Ratings and Reviews

5 out of 5

41 Ratings

41 Ratings

Six stars if I could


5/8/17 Update: Ernest Brock did an update to fix the worksheets crashing but also added a bunch of new features plus improved the vertical interface. Excellent update and still the best calculator out there. Now worth seven stars.

Absolutely blows the physical HP12 out of the water. Faster, Better, Stronger!!! The calculator itself is a perfect match ( with some extra features) but the real differentiating power is in the spreadsheets that come imbedded with the calculator. Also, three more very nice features: you can see the numbers you entered for NPV type calculations; the backspace key; and the color of the screen changes upon launching to tell you the app is ready for use.

I can't believe the price was 6 bucks. I would have paid more ( but didn't have to... even better)

The Best Financial Calculator––and Best Developer


In an earlier review I gave this phenomenal app 5 stars but wanted to give it 100. Now, I want to give it 1,000. A couple of days ago, I reported what looked like a glitch––caused by Apple––NOT the app. The developer, Ernie Brock wrote me a personal e-mail and followed-up VERY quickly with a fix.

Hands down, this is the #1 calculator of its kind on the market in this CPA's opinion. I use this every day for a wide variety of reasons, and I don’t think I’ve begun to plumb its depths. In addition to doing all the HP 12-C calculations, it has templates for leases, loans, time value of money, multi-year financial ratios, foreign exchange calculations, etc.

One of the best features is an electronic "tape," which, amazingly, can be e-mailed as a PDF file for printing if need be. This makes the app substantially more valuable than any physical calculator or any comparable app.

When I bought this app for my iPhone, I expected to have to pay again for my iPad, but, no, I could download it onto my iPad for no additional cost. This calculator is outstanding. The developer, Ernie Brock, is a genius.

I recommend this fantastic app HIGHLY.

Still the best HP12C App Ever!

Carlos Borromeo

The updates on this app keep it at the top of my list of most used apps on my iPhone and other Apple devices.

I have always owned at least three HP 12C handheld calculators since these came to the market decades ago. I still do today but now that I am on my iPhones and iPads most of every waking hour I find it so convenient to be able to click on Ernest Brock's 12Calc on my iPhones and iPads while working numbers on these devices.

I have been a user of Ernest Brock's 12Calc from its first appearance and through its periodic updates with new features as Mr. Brock has again done with this superb 12Calc Version 2.2!

I am now 72 years old and since these came out in the market I have used and recommended to family and friends both the HP12C handheld calculator and Ernest Brock's 12Calc app. I will continue to use and recommend these to anyone looking for timeless products that are classics in their industry.

Good job, HP and Ernest Brock! Your excellent products enhance each other like supportive partners, which is how I view and use your products.


Ernest Brock
6 MB
Requires iOS 11.0 or later. Compatible with iPhone 5s, iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPhone 7, iPhone 7 Plus, iPhone 8, iPhone 8 Plus, iPhone X, iPad Air, iPad Air Wi-Fi + Cellular, iPad mini 2, iPad mini 2 Wi-Fi + Cellular, iPad Air 2, iPad Air 2 Wi-Fi + Cellular, iPad mini 3, iPad mini 3 Wi-Fi + Cellular, iPad mini 4, iPad mini 4 Wi-Fi + Cellular, 12.9-inch iPad Pro, 12.9-inch iPad Pro Wi-Fi + Cellular, 9.7-inch iPad Pro, 9.7-inch iPad Pro Wi-Fi + Cellular, iPad (5th generation), iPad Wi-Fi + Cellular (5th generation), 12.9-inch iPad Pro (2nd generation), 12.9-inch iPad Pro Wi‑Fi + Cellular (2nd generation), 10.5-inch iPad Pro, 10.5-inch iPad Pro Wi‑Fi + Cellular, and iPod touch.
Age Rating
Rated 4+
© Ernest Brock 2013-2017 All rights reserved.


  • Family Sharing

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

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