# Modulus Calculator > Calculator performing arithmetic operations within a specified modulus. (iPhone/iPad app by Theodore Dubois.) - Source: https://appshunter.io/ios/app/modulus-calculator/id1432356578 (this page in markdown: same URL + `.md`) - Developer: [Theodore Dubois](https://appshunter.io/developer/1432356577) - Category: Utilities - Price: Free - Rating: 4.80/5 from 8 App Store ratings · 6 written reviews indexed - Age rating: 4+ - Requires: iOS 11.0 · 1 MB - Languages: American English - Released: 2018-08-26 - Data updated: 2026-08-13 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/modulus-calculator/id1432356578/reviews.md ## What is Modulus Calculator? An app that looks like the regular calculator, but all the operations work in a modulus. Powers and inverses in a modulus are also supported (division is done by multiplying by the inverse). Tap the handy "mod" indicator to switch the modulus. ## Key features - Modulus-based calculations - Support for powers and inverses - Division via modular inverse - Easy modulus switching - Calculator interface ## Recent user reviews (6 of 6) All indexed reviews: https://appshunter.io/ios/app/modulus-calculator/id1432356578/reviews.md ### 4/5 — Confusion *2022-08-13* Great - But! (Using & for the x^y key and setting mod to 37; = for the equals key, and -> for the displayed result) : 10&20 x 7 = -> 34 10&20 = -> 26, ac 26x7 = -> 34 10&20 = x 7 = -> 33 !!! Why does touching the = key to see an intermediate result cause it to produce a wrong answer. It does this for all ax^b I’ve tried with all mod values. Is there a reason? Otherwise a really great app! ### 5/5 — good one *2022-04-05* thanks for making it free ### 4/5 — It ain't much, but it's honest work. *2021-07-08* It's really basic, such that you would probably only find it useful with another calculator if that calculator doesn’t have a modulus tool (or at least doesn’t have a modulus tool that saves the value that you're modulating by; requiring you to type the value in every single time...). Even then though, you probably would prefer to have a tool that would continuously run an equation with progressively changing variables. In my case, I was hoping to better visualize some equations to chew on the implications of the modulus tool, to develop a deeper intuition of cryptography with key signatures, but this is not an ideal tool for that either. The issue there is that every time you hit "=", the result of any modifications is automatically put through the modulus. An example: Let's say that we're trying to test the difficulty of finding a multiplicative-inverse (g^-1) of a combination of 'g' (publicly shared factor) and 'n' (the value to modulate by). You would first multiply g by some positive integer that acts as a secret key, or maybe a public key if you don't want to know the secret key first. if it's a large number, you may want to know the product first, but upon hitting the '=' you will only see the modulus output of the product, meaning you either need to have an exceedingly efficient mental multiplication ability, or use another calculator in combination with this one. Because of this, this app is most likely to be impractical for anyone to use, unless there is an update, which is probably not gonna happen as the dev. seems to no longer be maintaining this app. ### 5/5 — Excellent! *2019-06-21* Thanks for creating this easy to use Mod Calculator - very handy reference & works exactly as I would expect. A++ ### 5/5 — Great app *2018-08-26* Modulicious ### 5/5 — Amazing modulus app *2018-08-26* Theodore did a good job. I r8 8/8 m8. **Developer response:** Hi Ben ## Frequently asked questions about Modulus Calculator ### What is Modulus Calculator? Modulus Calculator is a utility app that functions like a standard calculator but performs all operations within a specified modulus. It supports powers and inverses, with division implemented through multiplication by the inverse. ### How do I switch the modulus in Modulus Calculator? You can switch the modulus by tapping the handy "mod" indicator on the calculator interface. This allows you to easily change the modulus for your calculations. ### Does Modulus Calculator support division? Yes, Modulus Calculator supports division by performing it through multiplication by the modular inverse. This is a standard method for division in modular arithmetic. ### What kind of operations does Modulus Calculator support? Modulus Calculator supports all standard arithmetic operations (addition, subtraction, multiplication, division) performed within a modulus. It also supports calculating powers and inverses in a modulus. ### Is Modulus Calculator free to use? Yes, Modulus Calculator is available for free. There are no costs associated with downloading or using its core functionalities. ### What devices is Modulus Calculator compatible with? Modulus Calculator is compatible with iPhones and iPods. It is designed for iOS devices. ### What is the age rating for Modulus Calculator? Modulus Calculator has an age rating of 4+. This indicates it is suitable for users of all ages, with no content restrictions. ### How often is Modulus Calculator updated? The latest version of Modulus Calculator is 1.0, last updated on August 26, 2018. As of the last update, it has not received further updates. ## Version history (last 1 release) ### 1.0 — 2018-08-26 This app has been updated by Apple to display the Apple Watch app icon. ## Apps similar to Modulus Calculator | App | Rating | Price | Category | | --- | --- | --- | --- | | [Modulo Calculator, iCalcModulo](https://appshunter.io/ios/app/modulo-calculator-icalcmodulo/id6443557633) | 5.0 (1) | Free | Utilities | | [Calculi: Scientific Calculator](https://appshunter.io/ios/app/calculi-scientific-calculator/id452182503) | 4.4 (374) | Free | Utilities | | [Programming Calculator](https://appshunter.io/ios/app/programming-calculator/id1481845623) | 4.9 (38) | Free | Utilities | | [On-Device AI: Private Suite](https://appshunter.io/ios/app/on-device-ai-private-suite/id6497060890) | 4.4 (162) | Free | Utilities | | [Modulo Calculator](https://appshunter.io/ios/app/modulo-calculator/id1514351751) | — | Free | Utilities | | [Puma Browser: fast & private](https://appshunter.io/ios/app/puma-browser-fast-and-private/id1456296154) | 4.3 (146) | Free | Utilities | ## More apps by Theodore Dubois - [iSH Shell](https://appshunter.io/ios/app/ish-shell/id1436902243) - [nasin sitelen Wakalito](https://appshunter.io/ios/app/nasin-sitelen-wakalito/id1569543076) All apps by Theodore Dubois: https://appshunter.io/developer/1432356577 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-13.*