Mathematics
Half-Life Calculator
Calculate the half-life, initial quantity, remaining quantity, or time elapsed for a radioactive or decaying substance.
How to Use
- Select the variable you want to solve for from the dropdown.
- Enter the values for the remaining 3 variables.
- The calculator will instantly compute the missing variable using the standard radioactive decay formula.
Formula
Decay Formula:
N(t) = N₀ × (1/2)(t / t½)
Where:
N(t) = Remaining Quantity
N₀ = Initial Quantity
t = Time Elapsed
t½ = Half-Life
N(t) = N₀ × (1/2)(t / t½)
Where:
N(t) = Remaining Quantity
N₀ = Initial Quantity
t = Time Elapsed
t½ = Half-Life
Half-life is the amount of time it takes for half of a substance (often a radioactive isotope or a medication in the bloodstream) to decay or be eliminated. The math behind half-life is an exponential decay function, meaning the substance never truly reaches zero mathematically, but becomes infinitesimally small.