# RLM-17BX Calculator — Finance Stats & Science Solver > General purpose calculator with specialized finance, business, and science worksheets. (iPhone/iPad app by R.L.M. Software.) - Source: https://appshunter.io/ios/app/rlm-17bx-calculator/id1593889938 (this page in markdown: same URL + `.md`) - Developer: [R.L.M. Software](https://appshunter.io/developer/289639238) - Category: Productivity, Finance - Price: Free with in-app purchases - Rating: 5.00/5 from 1 App Store ratings · 15 written reviews indexed - Age rating: 4+ - Requires: iOS 26.0 · 7 MB - Languages: American English - Released: 2021-11-23 - Data updated: 2026-10-24 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/rlm-17bx-calculator/id1593889938/reviews.md ## What is RLM? The RLM-17BX is a calculator for finance, business and science. It is designed to bring up the most of your iOS devices with an extensive set of worksheets and enhancements to cover most of the functions generally needed by financial, business, mathematical, engineering and scientific professionals. >Finance Worksheets: •Account Balance: Calculates the Balance of cash transactions and interest applied at arbitrary dates. •Amortization: Loan Amortization Schedule for a single or several loan payments. •Bond Price & Yield: Calculates the Price, Yield and Effective Duration of a Bond. •Black-Scholes Options: Calculates the CALL, PUT and “Greeks” values of a Black-Scholes European option. •Depreciation: Calculates depreciation with SL, SOYD, DB or MACRS methods and conventions. •Interest Rates: Nominal and effective interest conversion. •Time Value of Money: Calculates compound Interest problems. >Business Worksheets: •Bill-Tip-Split: Calculates the sharing of a Bill with Tip. •Break-Even: Analyze the following relation: Profit = (Price - Var.Cost) • Units - Fix.Cost •Currency Exchange with manual or on-line rates. •Inventory Turn Over. •Percents & Margins: Calculates %Change, %Total and Business margins. •Return on Investment. >Cash Flows Worksheets: •Equal Periods: Cash Flows occurring at regular time intervals. •Unequal Periods: Cash Flows occurring at arbitrary dates. >Statistics Worksheets: •Probability: 16 probability distributions. •One or Two variables Statistics. •Curve Fitting: 6 Regression models to fit a curve. >Scientific Worksheets: •Angles & Polar-Rectangular conversions. •Complex Numbers: Operations and functions with complex numbers. •Combinations & Permutations. •Logarithms, Trigonometric, Hyperbolic and Number Alteration functions. •Quadratic Equation solver •Triangle Solution: Solves a Plane & Spherical triangles. •3D Vectors: Operations and functions with vectors in Cartesian, Spherical or Cylindrical coordinates. •Universal Constants: All the NIST-CODATA physical constants values and descriptions. •Units Conversion: Physical units conversion completely customizable. >Conversion Worksheets: •Angles: Convert angle between DEG,RAD,GRAD,DMS and Slope %. •Currencies: world currencies conversions with manual input or on-line current rates. •Interest Rates: Nominal and effective interest conversion. •Units: Physical units conversions. >General Worksheets: •Date: Calculates days between dates with Actual, 360 or 365 days calendars. •Time: Calculates time intervals between different times. •Solver: Calculates arbitrary equations entered as text expression to solve any of the variables knowing the others. •Storage Registers: Store and perform operations directly over the calculators storage registers. •Memory Content: Clear, Back-Up or Restore part or all of the Calculator's memory. •General Settings: Customize many aspects of the calculator including formats & feedbacks. •Help Documents: Description and examples of all the calculator worksheets and features. •General Settings to set classic and new keyboard skins, RPN and algebraic logic, sounds, display format, etc. >Editors Worksheets: To create or edit data •(Date,Trx) List: Transactions and the dates they occurs for the "Account Balance Worksheet". •(Date.CF) List: Cash flows and the dates they occurs for the "Unequal Periods Cash Flows Worksheet". •(X,N) List: Cash flows and repetitions for the "Equal Periods Cash Flows Worksheet". •(X,Y) List: X and Y data samples for the Statistics worksheets. •Solver Equation: Algebraic expression for use in the "Solver" worksheet. •Units Database: Customize the "Units" worksheet. System requirements: iOS 26.0 or above. 30-day free trial, then a single one-time Lifetime Purchase. No subscription. License Agreement: http://www.apple.com/legal/itunes/appstore/dev/stdeula Disclaimer: THIS IS NOT A HEWLETT PACKARD CALCULATOR, AND IS NOT SPONSORED IN ANYWAY BY HEWLETT PACKARD OR ANY OF ITS SUBSIDIARIES. ## Key features - Finance worksheets (amortization, bond pricing, options) - Business calculations (bill split, break-even, currency) - Statistical analysis (probability, regressions) - Scientific functions (complex numbers, vectors) - Unit and currency conversions - Equation solver - Date and time calculations ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | Monthly Virtual Battery | $0.49 | per month | | Semi-Annual Subscription | $2.99 | per 6 months | | Annual Subscription | $5.99 | per year | **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Lifetime Purchase | $9.99 | one-time | ## Is RLM safe? Not enough ratings yet to assess RLM. ## Is RLM legit? RLM-17BX Calculator appears to be a legitimate app. The AppsHunter Legitimacy Score for RLM is 90 out of 100 points across 7 verification signals from App Store and developer data. ## Recent user reviews (10 of 15) All indexed reviews: https://appshunter.io/ios/app/rlm-17bx-calculator/id1593889938/reviews.md ### 4/5 — stack behaviour mismatch *2025-09-01, version 3.1.5* Love this calc, there’s an issue with the stack behaviour, described below, which is supposed to be fixed in the next release as per my comms with the developer. both 17bx and 19bx are affected. To reproduce: - Switch to RPN mode - Perform the following [1] [Enter] [2] [<-] [3] Expected stack contents: X=3, Y=1. Actual stack contents: X=3, Y=0, Z=1. See: P272 (Appendix E: the RPN Stack), “Clearing numbers” section of the HP 17Bii operation manual (linked in the documentation). I suspect it shouldn’t be pushing zero to the stack, according to the documentation and original 17BII behaviour. ### 1/5 — stack behaviour mismatch *2025-05-20, version 3.1.5* Don’t bother buying this, absolutely no customer support, waiting for this to be fixed since last July, reported a quality issue, nothing happens. Get the RLM-12 instead, it doesn’t have the problem. both 17bx and 19bx are affected. To reproduce: - Switch to RPN mode - Perform the following [1] [Enter] [2] [<-] [3] Expected stack contents: X=3, Y=1. Actual stack contents: X=3, Y=0, Z=1. See: P272 (Appendix E: the RPN Stack), “Clearing numbers” section of the HP 17Bii operation manual (linked in the documentation). I suspect it shouldn’t be pushing zero to the stack, according to the documentation and original 17BII behaviour. ### 4/5 — Calculations are Precise, but NOT ACCURATE. *2024-08-06* The calculator emulates the HP 17Bii calculator well, but it is not accurate. For example: In the >BUSINESS>PERCENTS & MARGINS menu for example: If the [Old Value] is 41.67 and the [New Value] is 80.00, the [% Change] is 91.98, but the calculator inaccurately registers the value as 92.00. Also in the Help section, the instruction booklet which is the exact copy of the Hewlett Packard 17Bii calculator, is not indexed with a FIND search feature. **Developer response:** We couldn't reproduce the inaccuracy you mentioned. Please be sure that the #PD value is set to 1.0 and perform the calculation of %CHG. ### 4/5 — Calculations are Precise, but NOT ACCURATE. *2024-08-04* The calculator emulates the HP 17Bii calculator well, but it is not accurate. For example: In the >BUSINESS>PERCENTS & MARGINS menu for example: If the [Old Value] is 41.67 and the [New Value] is 80.00, the [% Change] is 91.98, but the calculator inaccurately registers the value as 92.00. Also in the Help section, the instruction booklet which is the exact copy of the Hewlett Packard 17Bii calculator, is not indexed with a FIND search feature. ### 2/5 — stack behaviour mismatch *2024-06-06, version 3.1.5* both 17bx and 19bx are affected. To reproduce: - Switch to RPN mode - Perform the following [1] [Enter] [2] [<-] [3] Expected stack contents: X=3, Y=1. Actual stack contents: X=3, Y=0, Z=1. See: P272 (Appendix E: the RPN Stack), “Clearing numbers” section of the HP 17Bii operation manual (linked in the documentation). I suspect it shouldn’t be pushing zero to the stack, according to the documentation and original 17BII behaviour. ### 5/5 — HP 17BII+ *2024-05-20, version 3.1.5* This is the “One For All” finance calculator. It is based on the famous HP 17BII+ calculator. ### 5/5 — Units editor broken *2024-05-15* (Update) The developers responded to my support request and resolved the issue with the editor. It works as intended now. Excellent and responsive support! Unfortunately, one cannot create a conversion with reciprocal units, like L/100km to MPG. The SI value needs to be directly proportional to the Unit, not inversely proportional. Perhaps add an exponent constant in the formula to create a reciprocal? Regardless, I increased my rating. (Old review) There doesn't seem to be a way to add additional unit conversions and when editing an existing, even just changing the name, it resolves to zero. The only way to fix it is to reset all units to default. That being said most of the units one would need are there. It would be nice if there was also a fuel economy conversion, but I created my own using the solver. **Developer response:** This bug was solved in the last update (version 3.1.5 approved in April 27, 2024). Now you can create the Fuel Economy conversions in the Units Convenrsions database editor. ### 3/5 — Units editor broken *2024-03-27* There doesn't seem to be a way to add additional unit conversions and when editing an existing, even just changing the name, it resolves to zero. The only way to fix it is to reset all units to default. That being said most of the units one would need are there. It would be nice if there was also a fuel economy conversion, but I created my own using the solver. ### 5/5 — Outstanding *2024-02-29* Just love this one. Looks like my physical unit. His work on these calculator apps is just a work of art. Such fine attention to detail. Im a financial advisor and this is one of the best financial calculator apps in the store. I think i own pretty much all the calculator apps he has made. **Developer response:** Thank you very much for your review. We are commited to build the best possible calculator for iOS and is great to be recognized for that as you did. ### 3/5 — Doesn’t Show as Installed *2024-02-18* Great for TVM calculations. The app doesn’t show up in the list of installed apps on the main settings window. Makes me wonder if the app can be trusted. As much as I like the app I have uninstalled it. Hopefully it is really fully uninstalled. **Developer response:** It should appear in the Settings. Look for it almost at the end of the apps list. Anyway, you can trust it !!! We don't collect any data from the user, the app don't post any information in internet, and our apps are completely sandboxed. The only information we get from Internet is the online currency rate for the Currency Conversion menu and the help documents showed in the Help Documents view. ## Frequently asked questions about RLM ### What types of financial calculations can RLM-17BX perform? RLM-17BX offers specialized finance worksheets for account balance, loan amortization, bond price and yield, Black-Scholes options, and various depreciation methods (SL, SOYD, DB, MACRS). ### Does RLM-17BX support currency conversions? Yes, RLM-17BX includes currency conversion worksheets that can use manual input or online rates for world currencies. ### What scientific functions are available in RLM-17BX? The scientific worksheets in RLM-17BX cover complex numbers, logarithms, trigonometric and hyperbolic functions, triangle solutions, 3D vectors, physical constants, and unit conversions. ### Can RLM-17BX solve arbitrary equations? Yes, RLM-17BX features a solver that can calculate any variable in an equation entered as a text expression, provided the other variables are known. ### What are the subscription options for RLM-17BX? RLM-17BX offers a monthly virtual battery subscription for $0.49, a semi-annual subscription for $2.99, and an annual subscription for $5.99. ### How often is RLM-17BX updated? RLM-17BX was last updated on April 26, 2024, indicating regular maintenance and potential feature additions. ### What devices is RLM-17BX compatible with? RLM-17BX is designed for iOS devices, including iPhone, iPad, and iPod, and has an age rating of 4+. ### What do users think of RLM-17BX? RLM-17BX has an average rating of 4.1 stars from 8 ratings, suggesting generally positive user sentiment. ## Version history (last 5 releases) ### 4.0.1 — 2026-10-20 Fix of iOS accessibility issue. Now, the “Accessibility -> Display & Text Size doesn't affect the layout. ### 4.0 — 2026-10-15 Version 4.0: a fully reworked calculator engine and worksheets, refreshed help documents for every menu, improved display and settings, and many accuracy and stability fixes. ### 3.1.5 — 2024-04-26 Now you can listen music while using the calculator. ### 3.1.4 — 2024-04-04 New editor for the Unit Conversion Database. Fix a problem with some devices involving the edition of a units conversions and categories in the database. ### 3.1.3 — 2024-03-07 Fix a bug regarding Accessibility Setting that affect the look of the interface. 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Software - [RLM-10BX](https://appshunter.io/ios/app/rlm-10bx/id1563019331) - [RLM-19BX](https://appshunter.io/ios/app/rlm-19bx/id1597086394) - [RLM-12CX](https://appshunter.io/ios/app/rlm-12cx/id1613759385) - [RLM-12PX](https://appshunter.io/ios/app/rlm-12px/id1613770734) - [RLM-11CX](https://appshunter.io/ios/app/rlm-11cx/id1630739014) All apps by R.L.M. Software: https://appshunter.io/developer/289639238 --- *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 2026-10-24.*