Morphine Milligram Equivalent (MME) Calculator
Enter one or more opioid medications and their total daily dose to estimate combined MME/day.
What is a morphine equivalent (MME)?
Morphine Milligram Equivalent (MME) is a standard way to compare opioid doses across different medications. Because opioids vary in potency, MME translates a dose into an estimated equivalent amount of oral morphine per day.
Clinicians use MME to support risk assessment, prescription review, and opioid stewardship. It is not a direct dosing instruction by itself, but it can help identify higher-risk exposure levels.
How this calculator works
Step-by-step logic
- Select an opioid medication.
- Enter the total daily dose (or mcg/hr for transdermal fentanyl patch).
- The calculator applies a conversion factor.
- MME/day is calculated as: Daily Dose × Conversion Factor.
- If multiple medications are entered, all MMEs are summed.
Common conversion factors used in this page
| Medication | Assumed Route | Conversion Factor |
|---|---|---|
| Morphine | Oral | 1 |
| Codeine | Oral | 0.15 |
| Hydrocodone | Oral | 1 |
| Hydromorphone | Oral | 4 |
| Oxycodone | Oral | 1.5 |
| Oxymorphone | Oral | 3 |
| Tramadol | Oral | 0.1 |
| Tapentadol | Oral | 0.4 |
| Fentanyl Patch | Transdermal | 2.4 × mcg/hr |
| Methadone | Oral | Dose-dependent (nonlinear) |
Interpreting the result
Many clinical frameworks use MME thresholds as caution signals rather than absolute rules. A higher MME can correlate with increased overdose risk, especially when combined with sedatives, alcohol, sleep apnea, or serious cardiopulmonary disease.
- < 50 MME/day: Lower relative risk zone (still requires monitoring).
- 50 to < 90 MME/day: Elevated caution zone.
- ≥ 90 MME/day: High-risk zone requiring careful reassessment.
Limitations you should know
Why MME is not the whole story
- Patient response varies significantly.
- Cross-tolerance between opioids is incomplete.
- Methadone and fentanyl conversions are especially complex.
- Renal/hepatic disease, age, and drug interactions change safety.
- Immediate-release vs extended-release products behave differently.
Safer opioid-use checklist
- Review all active CNS depressants (benzodiazepines, alcohol, sedatives).
- Reassess pain, function, and side effects regularly.
- Use the lowest effective dose for the shortest practical duration.
- Consider naloxone for overdose risk mitigation where appropriate.
- Coordinate care through one prescriber/pharmacy when possible.
Bottom line: MME calculators are useful for comparison and safety screening, but prescribing and opioid rotation decisions should always be individualized and clinically supervised.