Site menu Touch Fin: the financial calculator for Android and iPhone
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Touch Fin: the financial calculator for Android and iPhone

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Figure 1: Touch Fin screenshot - iOS

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

Get it at App Store

Get it on Google Play

Emulators of Hp-1xc RPN calculators by EPx

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 paid 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" or "data entry-friendly" format, that is: 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 time-limited nor crippled in any way whatsoever. The paid versions are ad-free and have more features that are extrinsic to the calculator. If you use the free version and like it, consider buying one of the paid versions 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. Each version is updated at a different time for extra safety: if one version breaks due to some unforeseen problem in update, the other is still available.

Settings (iPhone version)

This app adds a panel to device Settings. There, you can toggle decimal point as comma and keypress sound.

Figure 4: Touch Fin screenshot

These items may also be configured within the application screen, using the following key sequences:

The app implements a menu that is accessible via the Android-standard menu soft button, by touching the upper left corner of the screen, or by keying RCL EEX.

The free version implements only a subset of the following options.

Saving copies of the memory

The paid versions allow to store and retrieve copies of the memory. his 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.

Saving copies of the memory in iPhone

Use the following key combinations to access this feature (paid versions only): The memories are stored locally as well as in iCloud. If you have configured iCloud in your devices, you can transfer memories between devices, provided that they are configured with the same iCloud account. Also, a new device will have access to the previously saved memories, so you don't lose anything when you exchange your iPhone for another one.

Vertical layout

Figure 5: Touch Fin screenshot

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

By default the layout follows automatically the phone's orientation. If you prefer to use a single layout all the time, you can lock it to vertical or horizontal at Settings (iPhone) or in the menu (Android).

The free and paid versions implement the same calculator. The paid versions offer many extra features:

Vertical layout The vertical layout can be more practical if you like to use your phone in portrait orientation.
Quick guide Touch the upper right corner of the screen to see a quick guide for some operations.
Visual feedback In addition to audible feedback, touched keys can show a visual feedback. This feature can be turned on and off at Settings, or by keying RCL g +.
Screen filling The Android version offers fullscreen mode, as well as different screen filling methods (stretch vs. non-distorted).
No sleep! The Android version can prevent the display from sleeping and locking, so the calculator stays lit on the screen during all the time you need it.
Haptic feedback The Android version offers haptic feedback as an option to audible feedback.
Increased sensitive area The area around the keys is also sensitive to touches. You don't need to touch the key spot-on; touching near the key is enough. Coupled with the visual feedback, this feature allows faster typing. (Press RCL g ON if you are curious to see the sensitivity map.)
Save memory The current calculator memory (including all registers and programming steps) can be saved. You can save as many memories as you want, e.g. if you have many programs and want to load them later.
No ads The development of the paid version is supported directly by you!

(*) make sure you have signed into iCloud (Settings -> iCloud), so the memories are effectively backed up and shared between your devices.

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 6: Screenshot of Touch Fin Palladium

Get it at App Store

Get it on Google Play

This version is a separate app from the Gold version. It shares all the features of the paid 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 7: 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

Get it at App Store

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

In Android, 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. The license is similar to Briefs'.

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). Also, Rhino is extensively used in development, for building and unit testing.
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