Opioid Conversion Calculator

Opioid conversion compares the analgesic potency of one medicine with another through an oral morphine milligram equivalent, or MME. The current daily dose is multiplied by a published conversion factor to estimate daily MME. That MME is then divided by the target medicine's factor to obtain a theoretical equianalgesic dose. These calculations provide a common reference, but they do not establish a safe prescription for an individual patient. The calculator uses commonly cited approximate factors for oral products: morphine 1, oxycodone 1.5, hydromorphone 4, codeine 0.15, tramadol 0.1, and tapentadol 0.4. For example, 60 mg of oral morphine is 60 MME and corresponds arithmetically to 40 mg of oral oxycodone before adjustment. Sources and health systems may use different factors, especially as evidence evolves, so clinicians must follow the applicable formulary and guidance. Cross-tolerance between opioids is incomplete. A patient tolerant to one drug may be more sensitive to another despite an equianalgesic table. Clinical references therefore commonly advise reducing the calculated target dose, often by 25% to 50%, then titrating according to pain, function, sedation, respiratory status, organ function, age, frailty, and concurrent medicines. This tool applies the entered reduction after calculating the theoretical target dose. Linear conversion is not appropriate in every circumstance. Methadone has dose-dependent, nonlinear conversion and a long, variable half-life. Transdermal and intravenous products use different units and routes. Buprenorphine has distinctive receptor pharmacology. Fentanyl, methadone, high doses, rapid switches, renal or hepatic impairment, pregnancy, and palliative care often require specialist protocols. For safety, those complex options are not included in this simple oral calculator. Opioids can cause fatal respiratory depression, particularly during initiation, dose escalation, or combination with alcohol, benzodiazepines, sedatives, or other respiratory depressants. Never change, stop, share, or combine opioid medicines based on an online result. A licensed prescriber should verify the drug, formulation, route, total daily use, rescue doses, and monitoring plan. Patients and caregivers should know overdose warning signs and how to use naloxone where available. Seek emergency help for slow or absent breathing, inability to wake, or blue or gray lips.