Decay Lab vs Euler Gamma
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Decay Lab
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DecayLab makes radionuclide decay calculations and radiation unit conversions quick and straightforward. Designed for nuclear medicine professionals, researchers, educators, and students, it provides a clean, focused workflow that works entirely offline. Key features: • Calculate radioactive decay for a wide range of radionuclides • View activity at different reference and calculation times • Apply decay corrections quickly and consistently • Work with Bq, kBq, MBq, GBq and TBq, alongside nCi, µCi, mCi and Ci • Convert absorbed dose in Gy and rad, and equivalent dose in Sv and rem • Convert dose rates per second, minute, hour or day • See one value in every other unit at once, rather than one pair at a time • Access built-in radionuclide half-life data for 1,625 nuclides • Use all calculation features without an internet connection Gray and sievert are kept in separate tables. Converting between them requires a radiation weighting factor, which is a judgement about radiation type rather than a unit conversion, so DecayLab does not offer it. DecayLab is useful for: • Nuclear medicine technologists • Medical physicists • Radiation safety professionals • Researchers and educators • Students in nuclear medicine and related fields Whether you're checking an activity value, preparing calculations for a workflow, or studying radioactive decay, DecayLab keeps the process clear and efficient. Important: DecayLab is a calculation and educational tool. Results should be independently verified before being used in clinical, diagnostic, therapeutic, or safety-critical decisions.
Euler Gamma
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The all-in-one calculator suite for industrial gamma radiography professionals. Whether you're planning an exposure, calculating safety boundaries, or verifying ASME compliance — Euler Gamma delivers accurate results instantly, right from your pocket. Trusted by NDT technicians, RSOs, and radiography crews worldwide. WHAT YOU GET • Decay Calculator — Activity remaining after any elapsed time for Ir-192, Se-75, and Co-60 • Dose Rate Calculator — Inverse-square law with real-time results in mR/hr, µSv/hr, and more • Barricade Calculator — Safety boundary distances per NRC 10 CFR 20 guidelines • HVL Shielding Calculator — Half-Value Layer attenuation for Steel, Lead, Concrete, and more • Unsharpness Calculator — Geometric unsharpness (Ug) with ASME V Article 2 pass/fail checks • Reference Data — Built-in gamma constants, material properties, and occupancy factors BUILT FOR THE FIELD • Works offline — no internet required at the job site • Clean, fast interface designed for one-handed use • Supports both SI and US customary units • Results you can screenshot and share instantly COMPLIANCE YOU CAN TRUST Physical constants validated against NIST, ICRP, and NRC publications. ASME Section V limits built-in. Know your numbers are right — every single time. Download Euler Gamma today and make every shot safer and more precise.
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Verdict
The clearest difference is update cadence: Decay Lab at every 4 days against Euler Gamma's every 9 days. On price, ads, in-app purchases and device support 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.
Decay Lab ships an update every 4 days, Euler Gamma every 9 days. The most recent releases landed on September 15, 2026 and September 9, 2026 respectively.
| Parameter | Decay Lab | Euler Gamma |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 4 days — better | Every 9 days |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 6 MB | 14 MB |
| Age rating | 4+ | 4+ |
| Developer | Carlos Uribe | 音 卢 |
In-app purchases
Decay Lab
No in-app purchases
Euler Gamma
No in-app purchases









