Morphine Milligram Equivalent (MME) Calculator
Total daily morphine milligram equivalents (MME/day) for up to three opioids with CDC 2022 conversion factors — oxycodone, hydrocodone, hydromorphone, methadone, fentanyl patch, tramadol and more.
How it works
MME/day = Σ (strength per dose × doses per day × conversion factor); fentanyl patch: MME/day = mcg/h × 2.4. CDC 2022 factors: codeine 0.15 · hydrocodone 1 · hydromorphone 5 · methadone 4.7 · morphine 1 · oxycodone 1.5 · oxymorphone 3 · tapentadol 0.4 · tramadol 0.2 · fentanyl transdermal 2.4.
Morphine milligram equivalents put different opioids on a common scale so that total daily exposure — and with it overdose risk — can be compared. The 2022 CDC Clinical Practice Guideline for Prescribing Opioids for Pain lists the conversion factors used here and notes that overdose risk rises with dose, without a single safe threshold; 50 MME/day and 90 MME/day are the levels most often used for extra caution. MME values are for risk assessment, not for switching a patient from one opioid to another: conversion tables do not account for incomplete cross-tolerance, and methadone and fentanyl in particular need specialist dosing.
Worked example
Oxycodone 10 mg four times a day: 10 × 4 = 40 mg/day × 1.5 = 60 MME/day — above the 50 MME/day level at which the CDC advises reassessing benefits and risks and offering naloxone.
Frequently asked questions
How do you calculate MME?
Multiply the daily dose of each opioid in mg by its conversion factor and add the results. For a fentanyl patch multiply the strength in mcg/h by 2.4.
Can I use MME to switch from one opioid to another?
No. The CDC warns that MME factors are for estimating overdose risk, not for conversion dosing. When rotating opioids, clinicians usually reduce the calculated equivalent dose by 25–50% for incomplete cross-tolerance and follow specialist guidance, especially for methadone.
Why did the tramadol and methadone factors change?
The 2022 CDC guideline updated tramadol from 0.1 to 0.2, hydromorphone from 4 to 5 and methadone to a single factor of 4.7, replacing the dose-dependent methadone factors used in 2016.
Is buprenorphine included?
No. Buprenorphine is not converted to MME in the CDC guideline, because its partial-agonist effect means it does not carry the same overdose risk per milligram.
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Dosing information for education and for checking by a qualified prescriber — always confirm the dose against the product label, the local formulary and the patient’s indication, allergies, age and renal function before giving any medicine.