Calculate Daily MME (Morphine Milligram Equivalents)
Enter one opioid regimen at a time. This tool estimates MME/day for educational and planning purposes.
Conversion factor used: 1.0
Important: This calculator does not replace clinical judgment. Conversion factors can vary by source, patient factors, route, cross-tolerance, and incomplete opioid equivalence.
What is a morphine equivalent (MME)?
Morphine milligram equivalents (MME) provide a common scale for comparing opioid doses. Because different opioid medications have different potencies, MME helps clinicians, pharmacists, and patients talk about total opioid exposure in one standardized number.
For example, 10 mg of oxycodone is not equal to 10 mg of morphine in potency. Converting to MME/day makes relative strength easier to compare and can support safer prescribing discussions.
How this morphine equivalents calculator works
The calculator uses a simple formula for most oral opioids:
- Daily opioid dose = dose per administration × administrations per day
- MME/day = daily opioid dose × conversion factor
For transdermal fentanyl patches, a common estimate is used directly:
- MME/day = patch strength (mcg/hour) × 2.4
Methadone is special. Its conversion is non-linear, so the calculator increases the conversion factor as the total methadone daily dose rises.
Reference conversion factors used in this page
| Medication | Typical factor in this tool | Notes |
|---|---|---|
| Morphine (oral) | 1.0 | Reference standard |
| Hydrocodone (oral) | 1.0 | Often similar to morphine mg-for-mg |
| Oxycodone (oral) | 1.5 | More potent than oral morphine |
| Hydromorphone (oral) | 4.0 | Higher potency opioid |
| Oxymorphone (oral) | 3.0 | Potent opioid; use caution |
| Codeine (oral) | 0.15 | Lower conversion factor |
| Tramadol (oral) | 0.1 | Common reference factor in MME tools |
| Tapentadol (oral) | 0.4 | Lower MME conversion than many opioids |
| Methadone (oral) | 4 to 12 (dose-dependent) | Non-linear conversion in this calculator |
| Fentanyl patch (transdermal) | 2.4 per mcg/hour | Estimated daily MME from patch strength |
How to interpret your result
Below 50 MME/day
This is often considered a lower-dose range, but risk is never zero. Monitor sedation, constipation, function, and side effects.
50 to 89 MME/day
This range is frequently treated as a caution zone. Reassess benefits and harms, evaluate alternatives, and check for interacting medications.
90 MME/day or higher
This level is commonly flagged as higher risk. A careful, individualized clinical review is recommended, especially if combined with other central nervous system depressants.
Practical usage tips
- Convert each opioid regimen separately, then add totals if needed.
- Double-check route (oral vs transdermal) before calculating.
- Use the same guideline source consistently in clinical workflows.
- Document assumptions when using MME for care planning.
Frequently asked questions
Is MME exact?
No. It is an estimate based on population-level conversion factors. Individual response can vary substantially.
Can I use this to switch medications on my own?
No. Opioid rotation and tapering should be supervised by a licensed clinician because incomplete cross-tolerance and patient-specific variables can significantly change safe dosing.
Why does methadone use special rules?
Methadone potency increases disproportionately with higher doses. A fixed linear factor can understate risk at larger daily amounts.
Bottom line
A morphine equivalents calculator is best used as a structured safety aid. It helps compare regimens, spot potentially high exposure, and support informed conversations between patients and clinicians. Always pair MME with clinical context and professional judgment.