Health

Drug Half-Life Calculator

Track drug elimination over time.

Initial Dose (mg)

Half-Life (hours)

Time Elapsed (hours)

Drug Remaining—

% Remaining—

Half-Lives Elapsed—

Time to <3% (~5 half-lives)—

Remaining = Dose × (0.5)^(time / half-life)
~97% eliminated after 5 half-lives.