Site menu Touch 11i: the scientific calculator for Android
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Touch 11i: the scientific calculator for Android

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Figure 1: Screenshot of horizontal layout

Touch 11i (formerly named EPx11C or Andro11C) is a scientific calculator for Android. It implements most features of the beloved HP-11C, including programming functions. The app uses the same engine of the HP-11C Web emulator. It aims to mimic all features (and limitations) of the real device.

Looking for an iPhone version? Click here to go to Touch RPN.

Get it on Google Play

Figure 2: Some reviews from happy users!


The calculator mimics the 11C as closely as practically possible. It shares the same limitations as an original 11C: 399 programming steps, 20 memory positions etc.

Touch the upper right corner of the screen to open a quick guide for some operations of the calculator:

Figure 3: Touch 11i - quick guide

Touch the upper left corner to copy the displayed value (the X register) to the clipboard. The value is copied in a "spreadsheet-friendly" format: no thousand separators and point as decimal separator.


The calculator is offered in two versions: paid and free (ad-supported).

The free version is not limited in any way whatsoever. The paid version is ad-free and has features beyond the calculator. If you use the free version and like it, consider buying the paid version to support the development of this app.

Free and paid versions are separate apps. Buying the paid version does not remove the free app from your phone, and you can keep both. Each version is updated at a different time for extra safety: if one version breaks due to some unforeseen problem, the other is still available.

Extra features of paid version:


Press the ON button to access the Settings panel.

Saving copies of the memory

The paid version allows to store and retrieve copies of the memory. This is especially useful to have many different programs available and ready to use (perhaps the programs would not fit in the memory all at once, or it is simply inconvenient to have them all in the same memory image). In any case, the whole memory, including all registers and configurations, is saved along with the program.

The memory operations can be found in the Settings panel.

Vertical layout

The paid version offers an alternative vertical layout, good for using in vertical (portrait) position.

By default the layout follows the phone orientation. If you prefer to use a single layout all the time, you can lock it to vertical or horizontal at Settings.

Figure 4: Screenshot of vertical layout

Hardware keyboard

If you have a hardware keyboard (USB or Bluetooth) connected to your phone, you can use some shortcuts to operate the calculator.

A B C !D \E H 7 8 9 /: ] T I J K P 4 5 6 X* [ U N Y Z return space 1 2 3 - O F G S R 0 . W +=

Differences from real calculator

First of all, it is important to mention that the calculator engine does not use a ROM dump. It is a clean-room implementation. So the results simply can not guaranteed to be exactly equal. Known deviations:

Terms of use

The calculator is offered "as is". There are no guarantees of precision, exactness, or aplicability to any given purpose. The developer has no responsability for any damages incurring from usage of this software.


Please use the comment section at this page, or contact me by e-mail if you have any issues or feedback.

Privacy policy

The ad-supported versions of this app collects and transmits the Advertising ID, exclusively for advertising and analytics purposes.

Apart from that, this app does not send any other user data to any remote party, and no data is shared with other apps.

When the user saves copies of the memory, they are written as files in the "storage area". Files in this area can be manipulated by any other app installed on the same phone. If this is a problem, remove these files from the SD Card once they fulfill their intended usage.

Source code

The source code of this software can be found at GitHub repositories for iOS and Android.

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