Pharmacology Calculators

These pharmacology calculators help estimate key drug parameters such as half-life, volume of distribution, dosing regimens, bioavailability, clearance, and renal excretion fraction. They are designed for students, educators, and researchers for quick, educational computations.

⚠ Disclaimer: These tools are for educational purposes only. Always verify calculations with authoritative pharmacology sources before clinical or experimental use.

Drug Half-life (t½) Calculator

Clearance (L/hr) Vd (L)

t½ = 0.693 × Vd / Cl

Volume of Distribution (Vd) Estimator

Dose (mg) Plasma Concentration (mg/L)

Vd = Dose / Plasma Concentration

Loading & Maintenance Dose Calculator

Target Concentration (mg/L) Vd (L) Clearance (L/hr) Dosing Interval (hr)

Loading = Conc × Vd, Maintenance = Conc × Cl × τ

Therapeutic Index (TI) Estimator

Toxic Dose (TD50) Effective Dose (ED50)

TI = TD50 / ED50

Bioavailability (%) Calculator

AUC Oral AUC IV Dose Oral (mg) Dose IV (mg)

F = (AUCoral × DoseIV) / (AUCIV × DoseOral) × 100%

Dose-Response EC50/IC50 Estimator

Max Response Half-max Response

EC50 ≈ Half-max / Max response × 100%

Area Under Curve (AUC) Estimator

Dose (mg) Clearance (L/hr)

AUC = Dose / Cl

Clearance (Cl) Calculator

Dose (mg) AUC (mg·hr/L)

Cl = Dose / AUC

Drug Accumulation Factor Calculator

Dosing Interval (hr) Half-life (hr)

R = 1 / (1 – e^-kτ), k = 0.693 / t½

Renal Excretion Fraction Estimator

Renal Clearance (L/hr) Total Clearance (L/hr)

fe = ClRenal / ClTotal × 100%