Dose Equivalent Calculator

Morphine Equivalent Dose (MED) is a standardized way to compare the potency of different opioid medications. Every opioid is assigned a conversion factor relative to morphine, so a patient's total daily opioid burden can be expressed as a single number in mg/day of morphine equivalents. This helps clinicians assess overall opioid load and overdose risk.

Research shows that patients taking 50 MED mg/day or more have twice the overdose risk compared to those on lower doses, and patients at 90 MED mg/day or more have a substantially higher risk still. Tracking total MED helps prescribers identify when a patient's combined opioid burden reaches clinically significant thresholds and consider risk mitigation strategies.

Fentanyl transdermal patches are dosed in micrograms per hour (mcg/hr). A commonly used conversion is that each 1 mcg/hr of transdermal fentanyl is approximately equal to 2.4 mg/day of oral morphine. For example, a 25 mcg/hr patch equates to roughly 60 mg/day MED.

No. This calculator is intended to estimate total opioid burden for risk assessment purposes only. It should NOT be used to determine doses when converting a patient from one opioid to another. Opioid rotations require careful clinical judgment, dose reduction for incomplete cross-tolerance, and consideration of patient-specific factors. Always consult clinical guidelines and a specialist when rotating opioids.

Methadone has a complex and variable conversion ratio that depends on the total daily dose. This calculator uses a conservative approximation of 3:1 (3 mg MED per 1 mg methadone) for lower doses, but clinicians should be aware that the true ratio can be much higher at larger doses. Methadone conversions should always involve specialist input.

No, this tool calculates opioid MED only. However, concurrent use of opioids and benzodiazepines significantly increases the risk of fatal overdose due to combined CNS depression and respiratory suppression. Clinicians should always assess benzodiazepine use alongside opioid prescribing and minimize concurrent use whenever possible.

Buprenorphine is a partial µ-receptor agonist with a ceiling effect on respiratory depression, making standard MED conversion factors unreliable and potentially misleading. Its unique pharmacology means it does not fit neatly into the equianalgesic table used for full µ-agonists. Separate clinical guidance should be followed for buprenorphine products.

The risk category is a general clinical guidance indicator based on total MED. A total below 50 mg/day is considered lower risk; 50–89 mg/day is moderate risk requiring additional caution; 90 mg/day or above is high risk and generally warrants thorough reassessment, enhanced monitoring, and consideration of naloxone co-prescribing per CDC guidelines.