r.Calc vs Dozecal
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
r.Calc
A straightforward calculator utilizing Reverse Polish Notation (RPN) for everyday calculations. It offers a four-level visible stack with a total capacity of 100 positions, providing visual feedback on stack fullness. Basic arithmetic operations and stack manipulation functions are included.
- Reverse Polish Notation (RPN) input
- Four visible stack levels
- 100-position stack capacity
- Progress bar for stack fullness
- Basic arithmetic operations
- Stack swap and recall functions
- Vibration feedback for errors
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This classic RPN (Reverse Polish Notation) calculator is a simple calculator for daily uses. The calculator features a four visible level stack, the total stack size has a total of hundred positions. A progress bar on the top of the screen shows you how the stack is full. For now the implemented operations are; Plus, Minus, Multiply, Divide, Opposite, Inverse. Other facilities like swap the first two number in the stack and recall from the last operation the two arguments should simplify the life. All keyboard errors are notified by a vibration.
Dozecal
This educational calculator promotes the use of Base Twelve (duodecimal) in math and science. It offers standard mathematical functions in both duodecimal and decimal modes, with automatic conversion between them. It utilizes Reverse Polish Notation (RPN) for calculations.
- Duodecimal and Decimal modes
- Automatic mode conversion
- RPN (Reverse Polish Notation) input
- Standard math functions
- Trigonometric operations (degrees)
- Educational tool for Base Twelve
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Dozecal is an educational RPN* calculator to promote the use of Base Twelve in math and science. The usual math functions are available in both DUODECIMAL and DECIMAL modes. Conversion is automatically made when switching from one mode to the other one. Trigonometric operations uses DEGREE as unit of measure. For more information about Base 12, please visit the Dozenal Society of America. * RPN : the Dozecalc calculator uses the Reverse Polish Notation (RPN). This notation seems complex but has many advantages over algebraic notation and is more intuitive once you have understood the idea. The calculator has a stack and any operation that requires two numbers is using the bottom stack layers (X and Y). Key ENTER to push the stack up and separate one number from the next. To perform arithmetic, key in the first number, press ENTER to separate the first number from the second, then key in the second number and then select and operator such as the numerical functions +, -, * or /. The result appears immediately after you press the numerical function key. The operator is keyed in only after both operands are in the stack. Example: calculate 3 + 4 Key sequence: 3 ENTER 4 + Result: 7 The result of any operation may itself become an operand. You do not need to press enter again to use the result. The "7" is already entered. Example: add 2 to the previous result Key sequence: 2 + Result: 9 Example: calculate 5 * (3 + 4) Key sequence: 3 ENTER 4 + 5 * Alternate key sequence: 5 ENTER 3 ENTER 4 + * Disclaimer: results and precision may occasionally be incorrect. Should you report them at johan@unumdesignum.com, and the author will be happy to fix !
Screenshots
Verdict
The clearest difference is price: Dozecal at Free against r.Calc's $0.99. Dozecal also leads on update cadence (every 10 months vs every 197 months). r.Calc's advantage is review sentiment (100% vs 75%) and iOS requirement (2.2.1 vs 12.0). On rating, 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
Dozecal is free to download; r.Calc costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 4.0 for r.Calc against 4.0 for Dozecal. Both are backed by a comparable volume of ratings — 3 and 4 respectively. Written reviews are what separate them: 100% of r.Calc's written reviews are positive against 75% of Dozecal's.
r.Calc ships an update every 197 months, Dozecal every 10 months. The most recent releases landed on June 10, 2026 and October 2, 2026 respectively.
| Parameter | r.Calc | Dozecal |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 4.0 (3 ratings) | 4.0 (4 ratings) |
| Positive reviews | 100.0% of reviews — better | 75.0% of reviews |
| Number of ratings | 3 | 4 — better |
| Update frequency | Every 197 months | Every 10 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 2.2.1 — better | 12.0 |
| Further details — not scored | ||
| Size | 0 MB | 27 MB |
| Age rating | 4+ | 4+ |
| Developer | Nicolas Jorand | Johan Kovacs |
Customer experience
r.Calc
Dozecal
In-app purchases
r.Calc
No in-app purchases
Dozecal
No in-app purchases









