Decay calc vs Rail Model Calc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Decay calc
This tool calculates the decay of radioactive isotopes over time, considering half-life for accurate activity predictions. It's useful in nuclear medicine, environmental monitoring, and radiation safety for handling and disposal of materials.
- Radioactive isotope decay calculation
- Half-life integration
- Activity prediction
- Decay constant determination
- Radiation dose calculation
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Decay calc is a tool used to calculate the decay of radioactive isotopes over time. It takes into account the half-life of the isotope and allows for accurate predictions of the remaining activity of the isotope at any given time. Decay calc can be used in a variety of fields, such as nuclear medicine, environmental monitoring, and radiation safety. It can help determine the appropriate handling and disposal of radioactive materials and ensure the safety of individuals who may come into contact with them. In addition to calculating the remaining activity of the isotope, decay calc can also be used to determine the decay constant, which is a measure of the rate at which the isotope decays. This information can be used to calculate the radiation dose received by individuals who are exposed to the isotope. Overall, decay calc is a useful tool for anyone working with radioactive materials or interested in learning more about radioactivity and its effects. It provides accurate and reliable calculations that can help ensure safety and proper handling of radioactive materials.
Rail Model Calc
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Overview This is a calculator app that includes calculation functions necessary when playing with railroad model. How to use After launching the app,the first screen that appears is the Home screen, which also serves as a menu. Swipe and tap the menu on the Home screen to transition to various calculation modes. You can use various calculation modes to perform calculations necessary for railway model track length and railway model production. This App offer the following calculation modes. •Home mode Home is available simple calculations. Set F1-F10 memory on this screen. •Normal mode It is a normal calculator. •Straight mode This mode calculates horizontal and vertical lengths when laying a straight rail diagonally. •Curve mode This mode calculates the vertical, horizontal, and diagonal lengths when laying a curve rail. •S-Curve mode This mode calculates the vertical, horizontal, and diagonal lengths when laying a s-curve rail. •Scale X/Y mode This mode calculates the scale. •Inch to MM mode This mode converts yards and inches to millimeters. For details on how to use it, there is a manual on "?" button. Disclaimer This calculator is for the railroad modeling hobby. The calculation results is the numerical value which be calculated by the developer. It may be different from the numerical value by model manufacturer. In particular, commercially available railroad model rails allow for dimensional errors. Therefore, the calculation results do not necessarily represent what the track layout cannot or can be done. This application is subject to change without notice. The developer assumes no responsibility for any loss or claims by third parties which may arise from the use of this application.
Screenshots
Verdict
The clearest difference is in-app purchases: Rail Model Calc at none against Decay calc's 1. Decay calc's advantage is ads (none vs shown) and update cadence (every 3 months vs every 14 months). On price, device support and iOS requirement 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. Decay calc sells 1 one-off in-app purchase. Rail Model Calc asks for nothing beyond the download.
Decay calc ships an update every 3 months, Rail Model Calc every 14 months. The most recent releases landed on October 8, 2026 and October 1, 2026 respectively.
| Parameter | Decay calc | Rail Model Calc |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (1 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 3 months — better | Every 14 months |
| Ads | No — better | Yes |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.2 — better | 15.4 |
| Further details — not scored | ||
| Size | 27 MB | 13 MB |
| Age rating | 17+ | 4+ |
| Developer | Alexey Baranov | Nobuyuki Kumakura |
In-app purchases
Decay calc
- Radio calc$0.99
Rail Model Calc
No in-app purchases
Questions
Is Decay calc free?
Is Rail Model Calc free?
Do Decay calc or Rail Model Calc have ads?
Which is updated more often, Decay calc or Rail Model Calc?
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