Twin-Calc 4+

Two calculators are in One App

Hiroyuki Ueda

Designed for iPad

    • 5.0 • 6 Ratings
    • $3.99



A simple and easy-to-use calculator app that combines two calculators into one.

Calculators are displayed side by side when the screen is horizontal, and vertically when the screen is vertical.

In addition to being able to perform separate calculations with each calculator, calculation results can be also copy and paste with one touch, so you can perform other calculations during calculations, making it even more convenient to use than you might imagine.

There is also a free version with ads. Please try it first.

1. Calculation results can be copy and paste between two calculators with one touch.
2. The result calculated can be input from one calculator to the other with one touch.
・When press the "→" key, the calculation result of the left calculator is entered at the end of the formula on the right calculator.
・When press the "←" key, the calculation result of the right calculator is entered at the end of the formula on the left calculator.
3. add, subtract, multiply and divide is performed.
Do multiplication and division first, then add and subtract.
4. Display the formula
The entered formula is displayed under the result, so you can easily check the operations.
5. Calculation results can be copied to iPhone’s memory
Calculation results can be pasted into other apps as text , so transcription errors will not occur.

Example of use
When you find a product for 988 yen for 3 pieces and a product for 1245 yen for 4 pieces while shopping, you can easily calculate "Which is cheaper?" And “How cheaper?"with this calculator.
1) Use the left and right calculators to find the unit price of the product (unit price = product price/number).
2) Tap the "- key" and "arrow key" on either the left or right calculator to calculate the unit price difference.

・Answer can be calculated up to 9 digits, minimum 0.000000001.
・If you divide a value by 0, it will be ∞ correctly, but this calculator will display "0".

The free version can be downloaded from

What’s New

Version 2.6.4

Support URL and Marketing URL have been updated.

Ratings and Reviews

5.0 out of 5
6 Ratings

6 Ratings

Ludacon ,

Simple. Effective. Why didn’t I think of that!

What a novel concept. On the surface it seems redundant but after considering how often we use math and I find myself pulling up the calculator I realized just how amazingly efficient this calculator layout is.

Simply a brilliant idea turned into a wonderfully useful app that will save me a ton of time in day to day life!

Developer Response ,

Thank you for downloading.
Also, thank you for your nice comment.
I am very happy.

Raithan Ellis ,

Convenience and Precision

The idea seems simple of having two calculators, but the result of how they work together is superior.

The ability to calculate two things side by side is helpful when comparing prices, performing complex conversions, validating finances, etc.

Wonderful idea, pure genius!

Developer Response ,

Thank you for downloading our App.
We are happy to hear your compliment.
Thank you!

jowmbo ,

Works great. Please add support for portrait orientation.

This is a very useful app. The only thing missing is the ability to use it without turning my phone. Please add support for portrait orientation.

Developer Response ,

Thank you for your happy comment.
We are very glad to read that.
According to your requests, we are now developing to realize.
Please wait for a moment.
Thank U

7 Oct
New App that two calculators can be used for both vertical and horizontal position has been released.
Please download.

App Privacy

The developer, Hiroyuki Ueda, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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