Radioactive decay calculations should take seconds, not interrupt your workflow. Decay Lab is a focused radionuclide decay calculator designed for nuclear medicine professionals, researchers, and students.
Choose a radionuclide, enter an activity and two points in time, and get the decay-corrected result instantly. No spreadsheets. No searching for half-lives. No internet connection required.
Download for iPhone, iPad, and Android.
Radiation decay made simple
Decay Lab brings the calculations you reach for most in a nuclear medicine setting into one clean, fast interface:
- Calculate decay instantly between any reference and target date and time
- Follow activity in real time with a continuously updated “Activity now” result
- Search more than 2,100 radionuclide records with verified half-lives
- Find clinically relevant radionuclides first, organized for PET, SPECT, therapy, and generator workflows
- Convert every common activity unit at a glance, Bq, kBq, MBq, GBq, TBq, nCi, µCi, mCi, and Ci
- Work completely offline, wherever the work takes you
- Use light or dark mode with a native interface built for each platform
From question to answer in three steps
- Choose the radionuclide. Browse by element or search the catalog. Nuclear medicine radionuclides are shown first, with clear PET, SPECT, therapy, and generator labels.
- Enter the reference. Set the known activity, unit, date, and time.
- Read the result. See the activity now and at your target time, in the unit that fits your workflow.
Need a conversion instead? Enter one value once and see the full becquerel and curie families together, no repetitive pair-by-pair conversions.
Built for the work of nuclear medicine
Use Decay Lab when you need to:
- Decay-correct a radiopharmaceutical activity before administration or imaging
- Estimate the activity remaining at a future time
- Work backward from a target time to a reference activity
- Convert quickly between SI and curie-based units
- Check a radionuclide half-life without searching online
- Teach or learn the relationship between activity, time, and half-life
It is a practical companion for nuclear medicine physicians, nuclear medicine technologists, medical physicists, radiation safety professionals, researchers, educators, and students.
Accurate by design
Both the Apple and Android apps use the same radionuclide catalog and the same tested decay physics. Unit conversions route through Becquerels as the common base, and clinically relevant nuclear states are curated so the app presents the state that matters, not just the first database match.
Decay Lab was created by me, and I want it to make a common calculation feel as quick and easy as it should.
What comes next
Decay Lab is only the beginning. I have more ideas for features and workflow improvements, and I will continue developing the app over time with one goal: to make the small, repetitive parts of our nuclear medicine work easier every day.
The people who use Decay Lab can help shape what comes next. If there is a calculation you reach for often, a step that feels more cumbersome than it should, or an improvement that would make the app more useful in your work, I would love to hear about it.
Ready to make decay correction the easy part?
Private by default
Decay Lab does not collect or store personal data. Calculations are performed locally on your device, and the app works without an account or an internet connection. Read the full privacy policy.
Support and feedback
If Decay Lab has been useful to you, consider leaving an honest rating or review on the App Store or Google Play. Reviews help other nuclear medicine professionals discover the app and help me understand what is working well.
For support, bug reports, feature ideas, or a radionuclide you would like to see reviewed, contact me through any of the social links in the footer of this page. That is the best way to reach me directly and help shape future versions of Decay Lab.
Decay Lab is a calculation aid. Always follow your institution’s procedures and independently verify results used for clinical decisions.