Site menu Touch Fin: the financial calculator for Android
e-mail icon
Site menu

Touch Fin: the financial calculator for Android

e-mail icon
Figure 1: Touch Fin screenshot

Touch Fin (formerly known as Touch 12i or Andro12C) is a financial calculator for Android. It implements most features of the industry-standard HP-12C calculator, including programming functions.

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

Get it on Google Play

Figure 2: Some reviews from happy users!

Touch Fin uses the same engine of the time-proven HP-12C Web emulator. It aims to mimic all features (and limitations) of the real device.


The calculator mimics the HP real device as closely as practically possible, including details such as rounding up of n in financial calculations. It shares the same limitations as the real 12C: only 99 programming steps, 20 memory positions, etc.

Touch the upper right corner of the screen (in premium versions) to open a quick guide for some operations of the calculator.

Figure 3: Touch Fin 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 four versions: Free (ad-supported), Gold, Palladium and Black-Scholes Edition.

The free version is not limited in any way whatsoever. The premium versions are ad-free and have features beyond the calculator. If you use the free version and like it, consider purchasing one of the premium versions to support the development of this app.

Free and premium versions are separate apps. Buying the premium 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 premium versions:


Press the ON button to access the Settings panel.

Saving copies of the memory

The premium versions allow 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 premium versions offer 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: Touch Fin screenshot

Hardware keyboard

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

N I P M V H 7 8 9 /: ! \ # $ % E 4 5 6 X* [ ] D Y C return space 1 2 3 - O F G S R 0 . W += Z: correct typing (rubout)

Palladium version

The calculator is offered in a "Palladium" version, that follows the conventions of the HP-12C Platinum. It is capable of algebraic mode (including parentheses) and has more storage: 400 programming steps and 30 NPV/IRR memory positions.

Figure 5: Screenshot of Touch Fin Palladium

Get it on Google Play

This version is a separate app from the Gold version. It shares all the features of the premium versions.

Black-Scholes edition

Different from typical 12C emulators, this calculator does not implement some seldom-used features. On the other hand, comprehensive support for Black-Scholes calculations is present.

Figure 6: Touch Fin screenshot

Bonds and depreciation features of 12C are not implemented in this version! On the other hand, there is comprehensive support for Black-Scholes calculations. Read our manual to learn how to use Black-Scholes features.

Get it on Google Play

This version is a separate app from the Gold version. It shares all the features of the premium versions.

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, based mainly on calculator's manual plus experimentation. So the results simply can not guaranteed to be exactly equal. Other differences:

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. Always double-check results against other sources if you are going to take some actual financial decision!

Privacy policy

The app does not send any user data to any remote party, and it does not share data 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.


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

Source code

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

Third-party licenses

Rhino Javascript engine

This calculator may include the Rhino Javascript engine. The engine is released as free software (MPL 2.0 license).

e-mail icon