Custom Formulas

74 reviews
Content rating
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About this app

This powerful app lets you create your own custom formulas and then perform computations using them by prompting you for the input values.

This app is easy to use, but unlike simpler apps, multiple entered values can be fed into multiple formulas and multiple output values can be displayed. The output of one formula in a group can be fed into the next by using the same variable name.

Related formulas can be grouped into categories to make them easy to find. e.g. Maths formulas, Surveying formulas, Loan interest formulas etc.

The order of variables displayed to the user can be changed, as can the number of decimal digits of precision shown in the output fields.

Three example formulas are pre-installed with the app. In order of increasing complexity they are: slope percentage, compound interest, and point scale factor. There are also a growing number of formulas available to easily download directly in the app from a web sharing hub. Current categories include health, finance, and surveying.

A formula group can be exported or emailed, allowing you to share your creations with other users of the app.

The results from multiple computations using the same formula can be saved to a CSV file for later viewing in a spreadsheet. You can also choose to compute the sum of the formulas for a range of values of one of the input variables using the sigma button.

In addition to evaluating formulas, there is also a calculator tool and a linear equation solving tool on the main page menu.

You can view the online help here:
Updated on
Aug 2, 2023

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
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Ratings and reviews

69 reviews
Jeremy Thurman (Neamerjell)
August 26, 2020
I was originally looking for a programming app when I found this one. I watched the video and this is above and beyond the functionality I was initially seeking! I would love to see more in depth documentation or a user manual. I received developer feedback on the usage of the 'if()' statement. Turns out I was not using it correctly. Update: The developer replied to my email with some excellent feedback and examples! Now 5 stars!
5 people found this review helpful
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A Google user
April 18, 2020
Its good but still needs tweeking. I like the app and it's functionality, the biggest issue I have is it keeps forcing every number I input and the outputs, into scientific notation, including constants I put into formulas, which isn't an issue if that's what you want. But I don't always like using SN, because sometimes I just need to see my actual numbers without having to do the extra rearrangement in my head, especially if I'm a bit tired. Needs an option to fully disable SN.
1 person found this review helpful
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April 19, 2020
I'm not seeing this when I use it. Email me using contact details at to give an example so I can test.
john mcilroy
December 17, 2020
Excellent app, but, what would make it even better would be the app database saved somewhere that doesn't need root to play around with. I find it easier to edit the database on the PC. That way I also have a backup copy. Any chance this could be done?
1 person found this review helpful
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December 19, 2020
You can export all the formulas for a category to *.cf text files on your phone's storage with the export option on the menu, then copy them to your PC, edit them there using Notepad, then import them back into the app using the new "import multiple" option when done. That's probably better than working with a database whose schema may change.

What's new

8.8: Updated to target Android SDK 33.
8.7: Bug fix.
8.6: Added min(), max(), and avg() functions which each take two values.
8.5: Added an option under the "Copy database" button on the "About" dialog to restore the internal database from a copy in the app folder.
8.4: Added button on "About" dialog to copy internal database to app data area for backup purposes.
8.3: Added options to show tenths of seconds and hundreds of seconds for output variables. Bug fix.