CalcMountain

Half-Life Calculator

Solve half-life problems for radioactive decay and exponential processes. Find the remaining quantity after a given time, or determine the half-life from initial and final amounts.

Inputs

Results

Remaining

25.00

% Remaining

25.00%

Half-Lives

2.00

Half-Life Results

ParameterValue
Initial Amount100
Remaining Amount25
Percent Remaining25.0000%
Amount Decayed75
Half-Life5,730
Time Elapsed11,460
Half-Lives Elapsed2.0000
Decay Constant (λ)1.209681e-4
Mean Lifetime (τ)8,266.6426
FormulaN(t) = N₀ × (½)^(t/t₁/₂)

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