A morphine milligram equivalent expresses any opioid dose in terms of the equivalent amount of oral morphine, using fixed conversion factors. It lets clinicians compare and total doses across different opioids to gauge overall opioid burden and overdose risk.

Which conversion factors does this use?

The published CDC factors: morphine 1, hydrocodone 1, oxycodone 1.5, hydromorphone 5, oxymorphone 3, codeine 0.15, tramadol 0.1, tapentadol 0.4, plus banded methadone factors and 2.4 per mcg/hr for fentanyl patches.

Why are 50 and 90 MME flagged?

CDC guidance advises increased caution and monitoring at or above 50 MME per day and careful justification and overdose-risk review at or above 90 MME per day. The tool highlights when a regimen crosses these thresholds.

Why is methadone banded?

Methadone has a non-linear, dose-dependent conversion: its factor rises from 4 to 12 as the daily dose increases. Pick the band that matches the patient's total daily methadone dose. Methadone conversions are complex and should involve a specialist.

Can I use MME to switch opioids directly?

No. MME is for assessing total daily burden and overdose risk, not for calculating an exact rotation dose. Incomplete cross-tolerance means a direct MME swap can overdose a patient, so opioid rotation needs clinical dose reduction and expertise.

Opioid MME Converter (Morphine Milligram Equivalents)

Morphine milligram equivalents (MME) put every opioid on a single morphine scale so a clinician can see a patient’s total daily opioid burden at a glance. This converter totals a multi-drug regimen and flags the CDC risk thresholds.

How it works

Each opioid has a published CDC conversion factor. For each drug on the regimen, the daily contribution is:

daily MME = dose_per_administration * times_per_day * conversion_factor

The factors used include morphine 1, hydrocodone 1, oxycodone 1.5, hydromorphone 5, oxymorphone 3, codeine 0.15, tramadol 0.1, and tapentadol 0.4. Fentanyl transdermal patches are dosed in mcg/hr and use a factor of 2.4, so a 25 mcg/hr patch is about 60 MME/day. Methadone uses banded factors (4 to 12) because its conversion rises with dose.

Example

A patient takes oxycodone 10 mg four times a day. That is 10 × 4 × 1.5 = 60 MME/day. Adding a 25 mcg/hr fentanyl patch (25 × 1 × 2.4 = 60 MME/day) brings the total to 120 MME/day, above the 90 MME risk threshold.

Notes

MME is a tool for assessing overall burden and overdose risk, not for directly rotating between opioids — incomplete cross-tolerance makes a straight MME swap dangerous. Methadone and buprenorphine in particular have non-linear, specialist conversions. This calculator is educational and runs entirely in your browser.