Drug Half-Life Calculator
Calculate drug elimination kinetics including remaining concentration, time to target levels, and steady state timing based on half-life.
Important Health Disclaimer
This calculator provides general health information based on standard medical formulas and WHO guidelines. Results are for informational and educational purposes only and should not be considered as professional medical advice, diagnosis, or treatment recommendations.
For health concerns, medical conditions, fitness plans, or dietary decisions, please consult with qualified healthcare professionals, licensed physicians, registered dietitians, or certified fitness trainers who can evaluate your individual health status and medical history.
Individual health needs vary significantly. These calculations are general estimates and may not be appropriate for everyone, especially those with existing medical conditions, pregnant women, children, or elderly individuals.
Not a substitute for professional medical advice
Drug Parameters
Peak or starting drug level
Level you want to reach (optional)
Remaining Concentration
6.25 units
After 4.00 half-lives
Time Estimates
Time to target (10 units): 19.9 hours
Time to 90% elimination: 19.9 hours
Time to 99% elimination: 39.9 hours
Steady state (5 half-lives): 30.0 hours
Key Points
After 4-5 half-lives, drug reaches steady state or is essentially eliminated
Each half-life reduces concentration by 50%
Elimination Reference
| Half-Lives | % Remaining | % Eliminated |
|---|---|---|
| 1 | 50.00% | 50.00% |
| 2 | 25.00% | 75.00% |
| 3 | 12.50% | 87.50% |
| 4 | 6.25% | 93.75% |
| 5 | 3.13% | 96.88% |
| 6 | 1.56% | 98.44% |
| 7 | 0.78% | 99.22% |
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