MME Calculator (CDC 2022)
For healthcare professionals. MME values estimate total daily opioid exposure and must not be used to convert a patient from one opioid to another.
Opioids the patient takes
Add each opioid with strength and doses per day,
then tap Calculate MME/day.
MME Calculator – Morphine Milligram Equivalents per Day
This free MME calculator works out a patient's total daily opioid dose in morphine milligram equivalents (MME/day) using the conversion factors published in the CDC Clinical Practice Guideline for Prescribing Opioids for Pain – United States, 2022. Add every opioid the patient takes – tablets, capsules, liquids or fentanyl patches – with the strength per dose and the number of doses per day, and the calculator shows the MME for each medicine and the combined total.
MME is used by prescribers, pharmacists, prescription drug monitoring programmes (PDMPs), insurers and researchers to compare the overall opioid exposure of different regimens and to identify patients who may be at higher risk of overdose.
How to Use the MME Calculator
- Select the opioid from the list.
- Enter the strength per dose in mg – or in mcg/hr for a fentanyl patch.
- Enter the number of doses per day (not needed for patches).
- Add every other opioid the patient uses, including "as needed" medicines at the maximum prescribed frequency.
- Tap "Calculate MME/day" to see the MME for each medicine and the total.
MME Formula
MME/day = Strength per dose × Doses per day × Conversion factor
For a fentanyl transdermal patch: MME/day = patch strength in mcg/hr × 2.4. The total daily MME is the sum of the MME/day of all opioids taken.
CDC 2022 MME Conversion Factors
| Opioid | Conversion factor |
|---|---|
| Codeine | 0.15 |
| Fentanyl transdermal (mcg/hr) | 2.4 |
| Hydrocodone | 1 |
| Hydromorphone | 5 |
| Methadone | 4.7 |
| Morphine | 1 |
| Oxycodone | 1.5 |
| Oxymorphone | 3 |
| Tapentadol | 0.4 |
| Tramadol | 0.2 |
The 2022 guideline updated several factors compared with the 2016 version – notably methadone (from a dose-tiered factor to a single factor of 4.7), hydromorphone (from 4 to 5) and tramadol (from 0.1 to 0.2). Buprenorphine is not included because, as a partial agonist, it does not have the same overdose risk profile per MME as full agonist opioids.
Worked Examples
| Regimen | Calculation | MME/day |
|---|---|---|
| Oxycodone 10 mg four times a day | 10 × 4 × 1.5 | 60 |
| Hydrocodone 5 mg six times a day | 5 × 6 × 1 | 30 |
| Tramadol 50 mg four times a day | 50 × 4 × 0.2 | 40 |
| Fentanyl patch 25 mcg/hr | 25 × 2.4 | 60 |
| Methadone 10 mg three times a day | 10 × 3 × 4.7 | 141 |
| Oxycodone 10 mg × 4 + tramadol 50 mg × 2 | 60 + 20 | 80 |
Interpreting the Total
The CDC 2022 guideline does not set rigid dose limits, but it notes that many patients do not gain additional pain relief or function from increasing opioid dosages to 50 MME/day or more, while the risk of overdose keeps rising. It advises clinicians to use the lowest effective dosage, to carefully evaluate individual benefits and risks when considering increasing the dosage, to avoid increases above levels likely to yield diminishing returns, and to offer naloxone when there is increased risk of overdose, including at dosages of 50 MME/day or more. The earlier 2016 guideline advised avoiding or carefully justifying dosages of 90 MME/day or more, a threshold still used in many state rules and PDMP alerts.
Why MME Must Not Be Used for Conversion
MME conversion factors are designed to estimate total opioid exposure, not to switch a patient from one opioid to another. Because of incomplete cross-tolerance, individual variation and differences in pharmacokinetics, converting doses with MME factors can lead to accidental overdose – especially with methadone, whose half-life is long and variable, and with fentanyl, whose absorption from patches differs between people. Opioid rotation should follow product labelling, specialist conversion tables with dose reduction, and close monitoring.
Limitations
- Factors are for oral formulations unless stated (fentanyl factor is for transdermal patches only).
- Buccal, sublingual and nasal fentanyl products, buprenorphine, and parenteral routes are not covered.
- The calculator does not adjust for kidney or liver function, age, or other medicines such as benzodiazepines that increase overdose risk.
- Different organisations (state programmes, insurers, research groups) may still use the older 2016 factors, so totals can differ between systems.
Frequently Asked Questions
What is MME?
Morphine milligram equivalent (MME) is the amount of morphine, in milligrams, that is roughly equivalent in potency to a given opioid dose. MME/day is the total daily opioid dose expressed in morphine equivalents.
How do you calculate MME per day?
Multiply the strength per dose by the number of doses per day and by the CDC conversion factor for that opioid, then add the results for all opioids.
What is the MME conversion factor for oxycodone?
1.5 in the CDC 2022 guideline, so 10 mg of oxycodone equals 15 MME.
What is the MME of a 25 mcg/hr fentanyl patch?
25 × 2.4 = 60 MME/day.
What changed in the 2022 CDC MME factors?
Methadone now uses a single factor of 4.7 instead of dose tiers, hydromorphone changed from 4 to 5, and tramadol from 0.1 to 0.2.
Can I use MME to switch from one opioid to another?
No. MME factors estimate exposure and risk; they are not safe for opioid rotation. Use product labelling and specialist guidance with dose reduction.
Is this calculator medical advice?
No. It is an educational tool for healthcare professionals. Patients should not change their medicines without talking to their prescriber.
Source: Dowell D, Ragan KR, Jones CM, Baldwin GT, Chou R. CDC Clinical Practice Guideline for Prescribing Opioids for Pain — United States, 2022. MMWR Recomm Rep 2022;71(No. RR-3):1–95.