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Half-Life Time of Medicine

This calculator helps determine the half-life (t½) of a medication in the body, which is the time it takes for its concentration to reduce by half. It’s useful for healthcare professionals, pharmacologists, and students to understand drug clearance and dosing intervals. The calculation is based on the initial concentration (Ao) and the elimination rate constant (Ko).

Half-Life Time of Medicine

Input Fields
Ao
mcg/mL
Ko
mcg/mL
t
hrs
If enabled, the result will update automatically when you change any value.

Half-Life Time Formula

Formula
$$t_{1/2} = 0.5 \times \left( \frac{A_0}{K_0} \right)$$

Where:

  • $$t_{1/2}$$ = Half-life time
  • $$A_0$$ = Initial peak concentration
  • $$K_0$$ = Elimination rate constant


The half-life of a drug reflects how quickly it is eliminated from the body, which is critical for determining proper dosing schedules. For example, if a medication has a short half-life, it may require more frequent dosing. Conversely, drugs with longer half-lives can be dosed less often. This calculator uses a simplified pharmacokinetic model assuming first-order elimination and steady initial values.

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