What you provide
What you provide
- Initial nuclei or activity, using the same scenario as the other inputs
- Elapsed time expressed in s, using the same scenario as the other inputs
- Half-life expressed in s, using the same scenario as the other inputs
PHYSICS / NUCLEAR PHYSICS
Radioactive Decay Calculator
Calculate expected remaining nuclei or activity after elapsed time and a constant half-life. Inspect the SI equation, substituted inputs, derived result, and physical limitations in one guided workspace.
- 01 Calculated in this tab
- 02 Values stay in this browser tab
- 03 Use boundary
Use boundary
Calculation path
Calculate expected remaining nuclei or activity after elapsed time and a constant half-life. The page evaluates the displayed equation from your supplied values and presents both symbolic and substituted KaTeX working so the arithmetic can be checked.
Calculation pathN=N_0(1/2)^(t/t_half) Conversion resultN=N_0(1/2)^(t/t_half)
What you receive
What you receive
- Expected remaining amount from the stated equation
- A symbolic formula plus substituted working with your values
- Visible assumptions, field guidance, and an authoritative learning reference
Use boundary
Choose the maximum decimal places shown. This does not increase source accuracy.
This continuous expectation model assumes one isolated decay mode and constant half-life; individual decay events are random.
Use internally consistent units and retain extra precision when carrying the result into another calculation.
Reviewed reference factors