Calculi: Scientific Calculator 4+

Unit & Currency Conversion

Michael Natole, Jr.

Designed for iPad

    • 4.4 • 355 Ratings
    • Free
    • Offers In-App Purchases


Calculators can be hard to use. Calculi plans to change all that.

Calculi is a smart calculator that is simple and easy to use, but with advanced features for power users. Whether you are trying to balance your checkbook or taking an advanced math class, this app will help you with all of your calculating needs.

Calculi doesn’t just add two numbers together but can solve complex expressions using the order of operations. The multi-line display allows for small or large expressions. So go ahead and calculate anything and everything! Press the 2nd button to reveal more scientific functions.

You can easily convert any of your calculations to a different unit across 17 categories such as length, area, and volume. Unit conversions are saved to your calculation history for easy review. A Calculi Pro subscription is required for this feature.

Traveling abroad? Not sure how much your lunch costs? Calculi has you covered with support for over 30 different currencies around the globe (data is updated daily from the European Central Bank). A Calculi Pro subscription is required for this feature.

Common constants from both mathematical and scientific fields (astronomical, chemical, electromagnetic, etc.) are included for use in calculations.

Calculi adapts to all of the latest iOS devices. Even better, multitasking on the iPad is supported in all orientations. Multi-window support is enabled on iPadOS so you can have Calculi wherever you need it. Interactive widgets are included for calculations on your home screen.

Gestures are fun. So why not?
- Long press the delete button to clear the display
- Long press the equals button to use the previous result or expression
- Long press the display to copy, paste, or share
- Long press any calculation item to reuse the expression or result

Don’t be selfish. This history tape can be shared either as a single thread or the entire tape using numerous methods such as email, messaging, or print. There is also an iMessage app so you can easily send calculations.

Calculi is also available on Apple Watch! Besides a four-function calculator, you will also find a tip calculator and counter.

Pair an external keyboard or trackpad to gain access to powerful shortcuts and full cursor support. You can hold down the command key on your keyboard to view all the available shortcuts.

Finally, if you enjoyed Calculi, please take some time to leave a review. Feedback is always appreciated for future updates.

This yearly subscription grants you access to the following:
- Unit Conversions
- Currency Conversions
- App Themes
- Colorful custom icons
- No Ads

If you enjoy using the app and want to support an independent app developer, please consider sending a tip.

Subscription Details
– Payment will be charged to iTunes Account at confirmation of purchase
– Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period
– Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal
– Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user’s Account Settings after purchase

Terms of Use:
Privacy Policy:

What’s New

Version 4.3

In this latest release, Calculi now includes interactive widgets for your home screen! Additionally, you will find the following features and improvements:
- Support for iOS 17, iPadOS 17, and watchOS 10
- All new Apple Watch app
- Option to speak actions and results
- New alternative app icons for Halloween, Thanksgiving, Christmas, Fall, and Winter
- Support for home screen quick actions

Ratings and Reviews

4.4 out of 5
355 Ratings

355 Ratings

Jess_Brat ,

Almost Perfect

This is dang near perfect: works with a keyboard! Works in Split Screen! No ads! Data not linked to your identity! History tape, keyboard shortcuts, shareable history… seriously, almost everything I want. There’s just one thing that makes it impossible for me to use: It doesn’t work in Slide Over. You can use the calculator itself in Slide Over, or you can view and share the history, but you can’t do both. Once you view the history, there’s no way to get back to the calculator in Slide Over, you must change to Split Screen, or close and re-open the app, that kind of thing. If this app ever gets Slide Over fixed, I will certainly download it again and definitely update my review. Until then, might as well delete it and keep using the calculator on my iPhone while working on the iPad. For what I’m looking for, this app is unusable.

UPDATE: This app is working perfectly now! I love it! The developer fixed it in the latest update, and I can confirm that now it works in Slide Over. It went from being unusable to being exactly what I want. Seriously, if I had the talent to be able to develop apps, this is what I would make—it checks all the boxes for me. I don’t need scientific functions or anything fancy, but I do need a history tape. I really like the tape in this app, because each equation has it’s own “bubble” in the history tape window, which makes recognizing each one simple. I kind of can’t wait for my friends to ask me if I use a calculator app on my iPad, so I can recommend Calculi to them and tell them about all the reasons they’re going to love it, too.

Developer Response ,

Thank you for your valuable feedback. The issue that you described has been fixed in the latest update. If you would so kind as to re-evaluate your review that would be most appreciated.

macxlab ,

It calculates, but the history is buggy

When I open the app and make a calculation, it does not appear in the history. If I go back to the home screen and then return to the app, my previous calculation now shows. When I do the next calculation, it replaces the info in the top tile instead of adding a tile. On the next calculation, things start working as they should. This is the pattern every time I clear the history.

I would give this app 5 stars if not for the buggy history. Without that feature it is a decent calculator, but then it is just a calculator. Please fix it for a great app!

MB1742 ,

Updated to add ads?

You updated the app to have ads? That’s so disappointing!

I also don’t like the added clutter of keys I will never use in the iPad app which forces the number keys to be centered instead of on the left as one would expect. I would have to limit my use to slide over in landscape orientation to keep the normal calculator feel.

Developer Response ,

Thank you for sharing your feedback. The old design will be available as an option in the next update coming soon.

If you do not wish to have ads, you can purchase access to Calculi Pro to remove them.

App Privacy

The developer, Michael Natole, Jr., 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 Used to Track You

The following data may be used to track you across apps and websites owned by other companies:

  • Identifiers
  • Usage Data

Data Linked to You

The following data may be collected and linked to your identity:

  • Identifiers

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Location
  • User Content
  • Usage Data
  • Diagnostics

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

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