Half-Life Calculator
Amount of a substance left after a given time.
How it works
Remaining = initial × (½)^(time ÷ half-life). Use the same time unit for both values.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.