CMCalc vs ThetaCalc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
CMCalc
This app emulates a classic 1980s computer math calculator, offering decimal arithmetic, binary conversions, and logic functions. It supports parentheses for complex calculations and includes modern features like copy/paste and landscape mode.
- Decimal arithmetic
- Binary conversions (decimal, binary, octal, hexadecimal)
- Binary logic functions
- Operator grouping with parentheses
- Hexadecimal input (A-F)
- Copy and paste results/functions
- Landscape mode
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The CMCalc application is a replica of the Casio CM-100 Computer Math Calc solar powered calculator that was sold in the mid 1980’s. It performs simple decimal arithmetic and basic binary conversions (decimal - binary - octal - hexadecimal) and binary logic functions. While it is a standard infix calculator, it supports operator grouping with parentheses. For hexadecimal calculations, the input keys include A through F. CMCalc application performs all the same functions as the calculator, and has the same look as the original. There are a couple features that were not conceivable in the 1980’s on a calculator … such as the ability to copy and paste the results or the entered function, and a landscape mode for devices with 4 inch or larger screens. The face of the calculator can be viewed in two modes including a traditional application style, and a photo replica of the original calculator face.
ThetaCalc
This utility app provides a Reverse Polish Notation (RPN) calculator. Users can extend its functionality by programming custom functions and equations using JavaScript.
- Reverse Polish Notation (RPN) calculator
- User-programmable functions
- JavaScript equation support
- Extensible functionality
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ThetaCalc is a RPN (Reverse Polish Notation) calculator which can be extended by functions and equations programmed by the user in JavaScript.
Screenshots
Verdict
The clearest difference is update cadence: ThetaCalc at every 3 months against CMCalc's every 45 months. ThetaCalc also leads on review sentiment (100% vs 75%). CMCalc's advantage is rating (4.5 vs 4.3) and iOS requirement (12.0 vs 17.6). On price, ratings volume, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
CMCalc holds the better App Store score, 4.5 against 4.3. Both are backed by a comparable volume of ratings — 6 and 4 respectively. Written reviews complicate that: 75% of CMCalc's written reviews are positive against 100% of ThetaCalc's, so the app with the better star average is not the one people write more warmly about.
CMCalc ships an update every 45 months, ThetaCalc every 3 months. The most recent releases landed on September 7, 2026 and June 1, 2026 respectively.
| Parameter | CMCalc | ThetaCalc |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (6 ratings) — better | 4.3 (4 ratings) |
| Positive reviews | 75.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 6 — better | 4 |
| Update frequency | Every 45 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 12.0 — better | 17.6 |
| Further details — not scored | ||
| Size | 4 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | William David | Felix Stehli |
Customer experience
CMCalc
ThetaCalc
In-app purchases
CMCalc
No in-app purchases
ThetaCalc
No in-app purchases
