Opioid Conversion Calculator
Estimate morphine milligram equivalents for common opioids. Clinical conversions need prescriber review and patient-specific judgment.
Frequently Asked Questions about the Opioid Conversion Calculator
What is a morphine milligram equivalent (MME)?
An MME expresses an opioid dose as the amount of oral morphine with roughly the same potency, so different opioids can be compared on one scale. You get the total by multiplying the daily dose by the opioid's conversion factor. For example, 60 mg of oxycodone per day times a factor of 1.5 equals 90 MME per day. The total daily MME is widely used to gauge overdose risk.
How does this calculator convert between opioids?
It turns the source dose into a total MME per day using the formula dose per administration times administrations per day times the source conversion factor. The result is an MME risk and comparison number only. CDC cautions that MME values should not be used to calculate a dose when switching between opioids, so this calculator does not suggest a target-opioid dose unless the source and target are the same drug. The factors include codeine 0.15, hydrocodone 1, morphine 1, oxycodone 1.5, oxymorphone 3, hydromorphone 5, and methadone 4.7.
Why does the result not show a target opioid dose?
Because an MME table is a risk-stratification tool, not a safe opioid-rotation protocol. Cross-tolerance, route, organ function, age, concurrent sedatives, and incomplete tolerance can make a mathematically equivalent dose unsafe. Use the MME/day result for comparison and threshold awareness only. A clinician must choose any real switch or taper plan.
What do the 50 and 90 MME per day thresholds mean?
The CDC flags total daily doses of 50 MME or more as carrying increased overdose risk that calls for caution and reassessment, and doses of 90 MME or more as high risk that should be avoided or carefully justified. This tool labels your result as lower, increased, or high based on those cutoffs. They describe the source regimen's MME total, not a target you should aim for.
Why is methadone handled differently?
Methadone uses the CDC 2022 MME factor of 4.7 in this calculator, but methadone remains a special high-risk case because its half-life is long and variable and its effect can accumulate. The calculator reports MME context only and never treats methadone as a dose-switching target. Methadone starts, changes, and tapers should only be handled by a clinician experienced with it.
Is this calculator medical advice?
No. It is for education only and is not a substitute for professional medical advice, diagnosis, or treatment. MME conversion factors are meant for analytic use, not as instructions for actually switching a patient between opioids. Any real opioid rotation requires individual assessment by a qualified clinician who can account for kidney and liver function, age, and other medications.
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