Opioid MME Calculator
Convert opioid doses to oral Morphine Milligram Equivalents (MME) and assess daily dosage risk level.
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How to use this calculator
Each opioid has an equianalgesic conversion factor to oral morphine. Multiplying the single dose by the factor gives MME per dose; multiplying by daily frequency gives total daily MME.
- 1
Select the opioid medication from the dropdown.
- 2
Enter the single dose in mg (or mcg/hr for fentanyl patches).
- 3
Enter how many doses the patient takes per day.
- 4
Review the total daily MME and the associated risk category.
Frequently asked questions
What is an MME?
A Morphine Milligram Equivalent (MME) is a standardised unit that allows comparison of different opioids. Every opioid is assigned a conversion factor relative to oral morphine, enabling clinicians to add up total opioid burden across different medications.
Why does the CDC flag 90 MME/day as high risk?
The CDC's 2022 Clinical Practice Guideline for Prescribing Opioids notes that patients receiving ≥90 MME/day are at substantially higher risk of overdose. Above this threshold, clinicians are advised to carefully justify the dose and co-prescribe naloxone.
Is the fentanyl patch calculated differently?
Yes. Fentanyl patches deliver a continuous dose in mcg/hr. The standard conversion is to multiply the patch strength (mcg/hr) by 2.4 to get approximate daily oral MME, because the patch delivers drug continuously over 24 hours.
Can I use this for buprenorphine?
Buprenorphine has a unique pharmacology (partial agonist with ceiling effect) and is not included in this calculator. Its MME conversion is complex and context-dependent — consult SAMHSA guidelines or a specialist.
Opioid MME Calculator — Morphine Milligram Equivalents
Why Opioid Dose Standardisation Matters
Patients are frequently prescribed multiple opioid medications or switched between them. Without a common unit, comparing dosages is difficult and dangerous. The MME framework, endorsed by the CDC, the VA, and most state prescription drug monitoring programs, converts every opioid to an equivalent oral morphine dose so total opioid burden can be assessed at a glance.
Using This Calculator Responsibly
This tool is designed to assist clinicians and pharmacists with dosage review. It should not be used to self-adjust opioid therapy. Conversion factors are population-level estimates; individual patient responses vary significantly. Always consult equianalgesic tables validated by your institution and the original CDC or VA/DoD clinical practice guidelines for definitive guidance.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →