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.

What is the Opioid MME Converter (Morphine Milligram Equivalents)?

Convert oxycodone, hydrocodone, fentanyl, buprenorphine, methadone, and other opioids to total daily morphine milligram equivalents using CDC conversion factors, with 50 and 90 MME risk flags. Runs in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

Opioid MME Converter (Morphine Milligram Equivalents)

Name: Opioid MME Converter (Morphine Milligram Equivalents)
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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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.

CDC conversion factors at a glance

Opioid	Conversion factor	Notes
Morphine (oral)	1.0	Reference standard
Hydrocodone	1.0	Same as morphine
Oxycodone	1.5	50% more potent per mg than morphine
Hydromorphone	5.0	High-potency oral opioid
Oxymorphone	3.0	—
Codeine	0.15	Weak; significant inter-patient metabolism variability
Tramadol	0.1	Dual mechanism; SSRI activity complicates risk
Tapentadol	0.4	—
Fentanyl patch	2.4 per mcg/hr	25 mcg/hr ≈ 60 MME/day
Methadone	4–12 (banded)	Factor rises as dose increases; specialist territory

Understanding the 50 and 90 MME thresholds

The CDC’s prescribing guidance identifies two key thresholds for overdose risk:

50 MME/day — at or above this level, the guidance recommends reviewing risk factors, discussing and offering naloxone, and reassessing pain treatment goals. Risk of overdose death roughly doubles compared to patients below 20 MME/day.

90 MME/day — at or above this level, the guidance calls for careful justification. If benefits do not outweigh risks, the guidance recommends working to reduce the dose. Exceeding 90 MME/day is associated with substantially higher overdose risk in the published literature.

These thresholds apply to the total daily MME across all opioids combined — which is exactly what this converter calculates when you add multiple drugs.

Worked example

For illustrative purposes: a patient takes oxycodone 10 mg four times a day. That is 10 × 4 × 1.5 = 60 MME/day — above the 50 MME threshold. Adding a 25 mcg/hr fentanyl patch (25 × 1 × 2.4 = 60 MME/day) brings the total to 120 MME/day, well above the 90 MME risk threshold. Both would appear as red flags in this converter.

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. It is not a substitute for clinical judgment or pharmacist consultation.