Drug Decay: 50% Rate Over 5 Hours
A substance decaying at 50% per period retains only about 3.125% of its original amount after 5 periods.
How to use this tool
- Enter initial value, decay rate per period and number of periods in the fields above.
- Results update instantly as you type โ or click Calculate.
- Read your remaining value and the full breakdown beneath it.
Model how a drug concentration drops when its elimination rate is 50% per hour over 5 hours.
Frequently asked questions
- What is the difference between decay rate and half-life?
- The decay rate r is the fraction lost each period; the half-life is the number of periods until only half remains. They are linked by tยฝ = log(0.5)/log(1โr).
- Does this assume continuous or discrete decay?
- This calculator uses discrete (period-by-period) decay. For continuous decay use A = Aโยทe^(โฮปt) with the half-life calculator.