Enter an initial amount
Use any positive mass or set the initial value to 100 to model percentage remaining.
Peptide Half-Life Calculator
Model first-order exponential decay from an initial amount, a literature-sourced half-life, and elapsed time. Results are theoretical and depend on the half-life entered.
LIVE CALCULATION
Exponential decay model
Use a half-life from an appropriate source and keep its experimental context in mind.
Remaining amount12.5%
Percent remaining12.5%
Percent reduced87.5%
Half-lives elapsed3
Current equation100 × (1/2)^(18 ÷ 6) = 12.5
This is a mathematical decay model, not a prediction of biological effect or storage stability.
METHOD & LIMITS
How this calculator works
Remaining amount = initial amount × (1 ÷ 2)^(elapsed time ÷ half-life).
ModelFirst-order exponential decay
Time unitsMinutes, hours, or days
OutputAmount and percent remaining
Important limitNot a biological prediction
Enter a sourced half-life
Use the same time basis as the elapsed-time field. The calculator can convert minutes, hours, and days.
Enter elapsed time
The result reports theoretical remaining amount, percent remaining, and elapsed half-lives.
Research calculation notice: This page performs mathematical conversions using values entered by the reader. It does not verify a product, select an amount, define a protocol, or provide medical or veterinary advice.
Peptide Half-Life Calculator FAQ
How is half-life calculated on this page?
The tool uses the standard first-order decay equation, multiplying the initial amount by one-half raised to the number of elapsed half-lives.
What remains after one, two, and three half-lives?
The theoretical remaining fractions are 50%, 25%, and 12.5%. Each additional half-life halves the previous amount.
Can I mix minutes, hours, and days?
Yes. The calculator converts both time inputs to hours before applying the equation.
Does half-life predict biological effect duration?
No. A reported half-life describes a decay model under defined conditions. Biological activity, distribution, metabolites, assay methods, and storage stability may follow different timelines.