Half-Life Time Calculator

Free half-life calculator. Calculate time for substances to decay to half their value. Essential for science and pharmacology.

Calculate how long it takes for a quantity to reduce to half its value through exponential decay. Used in radioactivity, pharmacology, and any field dealing with half-life concepts.

Common use cases

  • Radioactive decay calculations
  • Medication half-life in pharmacology
  • Chemical reaction rates
  • Physics and chemistry education
  • Environmental decay modeling

How to use

  1. Enter the initial quantity
  2. Enter the target quantity (or use half)
  3. Enter the known half-life period
  4. View time needed to reach target
  5. See decay curve visualization

FAQ

What is half-life?

The time required for a quantity to reduce to half its initial value through decay or elimination.

Can I calculate for any percentage?

Yes, calculate time to reach any percentage of the original, not just 50%.

What units are used?

You can use any time unit (seconds, minutes, hours, days, years) as long as you're consistent.