Drug concentration | C = C_{0} e^{−kt} | C = drug concentration at time t after C_{0} |

| | C_{0} = drug concentration at reference time |

| | k = elimination rate constant |

| | t = time between C and C_{0} |

Elimination rate constant | k = ln2/T_{0.5} | k = elimination rate constant |

| | ln2 = 0.693 |

| | T_{0.5} = half clearance time |

Volume of distribution | V = amount in body (μg)/actual C_{0} | V = volume of distribution |

| | Actual C_{0} = concentration at time of administration |

Area under curve | AUC_{0–∞} = FD/Vk | AUC_{0–∞} = area under curve (total drug dose) from time 0 to infinity |

| | F = fraction of drug absorbed |

| | D = dose |

| | V = volume of distribution |

| | k = elimination rate constant |

Clearance | CL = k × V | CL = clearance |

| | k = elimination rate constant |

| | V = volume of distribution |

Time to maximum concentration | T_{max} = (1/[k_{a} − k]) ln (k_{a}/k) | T_{max} = time to maximum concentration |

| | k_{a} = absorption rate constant |

| | k = elimination rate constant |