Opioid Calculator
Morphine milligram equivalents (MME) put every opioid on one scale so a clinician can see a patient’s total daily opioid burden at a glance. One milligram of morphine equals 1 MME; oxycodone counts 1.5 times its milligrams, fentanyl patches are measured in micrograms per hour with their own factor, and methadone gets special handling because its conversion is dose-dependent. Select the opioid, enter the total daily dose, and this calculator converts it using the CDC 2022 conversion factors, with the 50 and 90 MME caution thresholds the guideline sets.
Quick Answer
What MME actually measures
MME answers one question: how much opioid is this person exposed to, expressed in morphine units? It exists because “20 mg” means wildly different things across drugs: 20 mg of oxycodone is 30 MME, 20 mg of hydromorphone is 100 MME, and 20 mg of codeine is 3 MME. Health systems, prescription drug monitoring programs, and researchers use MME to flag high-burden regimens consistently. What it does not do is predict how any individual will respond, because tolerance, genetics, age, kidney and liver function, and interacting drugs all shift the real effect.
The conversion factors themselves are population averages from old equianalgesic studies, mostly single-dose trials in post-surgical or cancer patients. Critics, including pain researchers cited in the guideline debate, note that toxic effects like respiratory depression were not what those studies measured. That is why the CDC frames its dosage advice as guideposts for shared decision-making, not hard cutoffs, and why this calculator treats its own output as an estimate to discuss with a clinician rather than a number to act on alone.
The CDC 2022 conversion factors
| Opioid | Dose unit | MME factor | Example |
|---|---|---|---|
| Codeine | mg/day | 0.15 | 200 mg = 30 MME |
| Fentanyl transdermal | mcg/hr | 2.4 | 25 mcg/hr patch = 60 MME |
| Hydrocodone | mg/day | 1.0 | 20 mg = 20 MME |
| Hydromorphone | mg/day | 5.0 | 8 mg = 40 MME |
| Methadone | mg/day | 4.7 | 20 mg = 94 MME |
| Morphine | mg/day | 1.0 | 30 mg = 30 MME |
| Oxycodone | mg/day | 1.5 | 20 mg = 30 MME |
| Oxymorphone | mg/day | 3.0 | 10 mg = 30 MME |
| Tapentadol | mg/day | 0.4 | 100 mg = 40 MME |
| Tramadol | mg/day | 0.2 | 150 mg = 30 MME |
The table above is the CDC 2022 set, and the year matters. The older 2016 table used hydromorphone 4.0 (now 5.0) and tiered methadone factors that climbed with dose (now a single 4.7). Tools that never updated silently mix old and new numbers. Our calculator labels its source and year explicitly, so you always know which table produced the number. Note what is missing too: the 2022 table deliberately assigns no MME factor to buprenorphine, because as a partial agonist with a ceiling effect it does not carry the same dose-dependent overdose risk.
Worked example: 20 mg of oxycodone daily
A patient takes oxycodone 5 mg four times a day. Total daily dose: 20 mg. Multiply by the oxycodone factor of 1.5 to get 30 MME per day. The calculator shows this falls below the 50 MME line, the point where the guideline says to pause and reassess before any increase. If the same patient also used a 25 mcg/hr fentanyl patch, that alone would add 60 MME, and the honest clinical move is to add every opioid’s MME together, because the body does not care which prescription the milligrams came from. For combination tablets like oxycodone-acetaminophen, count only the opioid milligrams; the acetaminophen contributes nothing to MME.
What competing calculators get wrong
MME calculators look simple, which is why so many get the details wrong. The most dangerous error is the fentanyl unit trap: tools that accept a patch strength in mg, or never explain that patches use mcg per hour, can produce numbers off by a factor of a thousand. Next is the silent factor mix, where the page claims “CDC factors” but uses the 2016 hydromorphone value of 4 instead of the 2022 value of 5. Third is methadone treated as just another row: several tools apply a flat factor with no warning, even though methadone’s half-life swings from 8 to 59 hours and its potency climbs steeply with dose. Fourth, almost none warn against the actual misuse of the output: using a calculated MME to set the dose when rotating to a new opioid, when the standard of care is to reduce the calculated equianalgesic dose by 25 to 50% because cross-tolerance is incomplete.
Our winning moves: the unit selector that forces fentanyl into mcg/hr and warns when the units look wrong, explicit CDC 2022 labeling with the 2016 differences called out, a dedicated methadone caution that appears with the result, the combination-product rule (count the opioid only), and the rotation warning printed next to every result, not buried in a footer.
Costs and coverage around long-term therapy
Opioid therapy does not happen in a vacuum: naloxone co-prescribing, urine drug screening, and follow-up visits all carry costs, and non-opioid pain options like physical therapy depend heavily on coverage. If you are comparing what a long-term regimen costs under different plans, our Medicare Part D cost calculator estimates prescription drug spending, and our health insurance cost calculator helps you weigh monthly premiums against out-of-pocket exposure.
- MME puts every opioid on one morphine-equivalent scale; 20 mg of oxycodone daily is 30 MME.
- Use the CDC 2022 factors (hydromorphone 5.0, methadone 4.7) and know they changed from 2016.
- 50 MME/day is the pause-and-reassess line; 90 MME/day brings extra caution and diminishing returns.
- Fentanyl patches use mcg per hour, never mg per day. Unit errors here are potentially fatal.
- Never use calculated MME to set a rotation dose; incomplete cross-tolerance demands a 25 to 50% reduction.
- Methadone conversions are the least reliable of all and belong in specialist hands.
Frequently Asked Questions
Add up the daily total first: 10 mg twice daily is 20 mg per day. Multiply by oxycodone’s factor of 1.5 to get 30 MME per day. The same method works for any opioid: total daily dose in the correct units, times the factor from the CDC table.
25 mcg/hr x 2.4 = 60 MME per day. Enter the patch strength in mcg per hour, not milligrams. A 100 mcg/hr patch is 240 MME per day. Fentanyl patches are for opioid-tolerant patients only, take 12 to 24 hours to reach full effect, and absorption varies with heat and placement.
Methadone’s potency relative to morphine rises non-linearly as the dose increases, and its half-life varies enormously (8 to 59 hours), so a single flat factor is a rough approximation. The CDC 2022 table uses 4.7; the 2016 table used tiered factors up to 12 at high doses. Methadone conversions deserve specialist input, not a web calculator alone.
No. For a tablet like hydrocodone 5 mg / acetaminophen 325 mg taken four times daily, count only the hydrocodone: 20 mg per day x 1.0 = 20 MME. The acetaminophen contributes nothing to MME, though it matters for liver safety at high doses.
Three main things: hydromorphone’s factor rose from 4.0 to 5.0, methadone went from tiered factors (up to 12) to a single 4.7, and the guideline stopped presenting dosage thresholds as rigid rules, reframing them as guideposts for shared decision-making. Buprenorphine carries no MME factor in the 2022 table.
Absolutely not. MME monitors total burden; it cannot set rotation doses because cross-tolerance between opioids is incomplete. The clinical standard is to calculate the equianalgesic dose and then reduce it by 25 to 50%, with extra caution for methadone and fentanyl. Switching opioids is a prescriber decision.
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References
- 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(3):1-95. Source of the 2022 MME conversion factors and the 50/90 MME guidance.
- NYS Council of Health-system Pharmacists. 2022 CDC Clinical Practice Guideline for Prescribing Opioids for Pain: Changes Summary. Starting doses, the pause-and-reassess threshold at 50 MMED, and tapering updates. Accessed October 19, 2026.
- Centers for Disease Control and Prevention. CDC Guideline for Prescribing Opioids: MME Conversion Table (2016 factors for comparison: hydromorphone 4, tiered methadone). Accessed October 19, 2026.
- U.S. Food and Drug Administration. Opioid medications: approved labeling and safety communications. Fentanyl transdermal system labeling: opioid-tolerant patients only, 12-24 hours to therapeutic levels. Accessed October 19, 2026.
- Substance Abuse and Mental Health Services Administration. National Helpline: 1-800-662-4357 for substance use treatment referrals. Accessed October 19, 2026.
- American Society of Addiction Medicine. National Practice Guideline for the Treatment of Opioid Use Disorder. Methadone and buprenorphine treatment standards. Accessed October 19, 2026.
- Chou R, et al. The effectiveness and risks of long-term opioid therapy for chronic pain: systematic review for the CDC guideline. Ann Intern Med. 2015;162:276-286. Evidence base for diminishing returns at higher doses.
- Dasgupta N, et al. Cohort study of the impact of high-dose opioid analgesics on overdose mortality. Pain Med. 2016;17:85-98. Dose-dependent overdose risk informing the 50/90 MME thresholds.
- U.S. Centers for Disease Control and Prevention. Prescription Drug Monitoring Programs and naloxone co-prescribing guidance for high-dose opioid therapy. Accessed October 19, 2026.
- Washington State Agency Medical Directors' Group. Interagency Guideline on Prescribing Opioids for Pain. Equianalgesic dosing cautions and 25-50% reduction on rotation. Accessed October 19, 2026.