Morphine Milligram Equivalent (MME) Calculator
Morphine Milligram Equivalent (MME) Calculator
Morphine milligram equivalents by CDC’s 2022 factors and by its own pre-2022 factors side by side, because the two disagree by up to 2.55-fold — and MME is a surveillance construct that CDC itself says must not be used to convert one opioid to another.
Morphine milligram equivalents, CDC 2022 against CDC pre-2022
2 CDC factor sets, 10 opioidsOral tramadol, 400 mg a day — 100 mg four times a day
CDC’s two factor tables, and the three rows that changed
CDC 2022: codeine 0.15, transdermal fentanyl 2.4 per microgram an hour, hydrocodone 1, hydromorphone 5, methadone 4.7, morphine 1, oxycodone 1.5, oxymorphone 3, tapentadol 0.4, tramadol 0.2
CDC pre-2022: the same, except hydromorphone 4, tramadol 0.1, and methadone 4 (1–20 mg/day), 8 (21–40), 10 (41–60), 12 (61 and above)
- what MME is
- a regulatory and epidemiological construct. CDC’s own archived page describes the conversion file as “intended solely for research, analytic purposes” and has discontinued updating it. The figure drives surveillance, prescription monitoring programmes, claims edits and policy thresholds
- what MME is not
- a clinical equivalence for an individual. It is blind to CYP2D6 status, to tolerance, to renal function and active metabolites, to formulation and to route, and CDC’s third published caution is “Do not use the calculated dose in MMEs to determine the doses to use when converting one opioid to another”
- the three rows CDC changed in 2022
- hydromorphone 4 to 5, methadone 3 to a flat 4.7, tramadol 0.1 to 0.2. State Medicaid systems reprogrammed in 2023. No patient’s pharmacology changed; the convention did, and figures either side of the change are not comparable
- methadone, 4.7 against 4 to 12
- the sharpest version of the disagreement. CDC’s pre-2022 file made the factor rise with the methadone dose because methadone’s potency relative to morphine is not linear; the 2022 table replaced the four bands with one number. At 80 mg of methadone a day the two CDC answers differ 2.55-fold
- 50 MME a day
- the figure CDC’s own decision-support logic fires at, and the dosage at which its clinical guidance lists “Taking higher dosages of opioids (e.g., ≥50 MME/day)” among the reasons to offer naloxone. What the guidance asks for there is documentation, review and a conversation — not a ceiling and not a prohibition
- 90 MME a day
- the 2016 guideline’s figure: clinicians “should avoid increasing dosage to ≥90 MME/day or carefully justify” going above it. The 2022 guideline removed the number from the recommendation and says in its own introduction that it aims to discourage “the misapplication of opioid pain medication dosage thresholds as inflexible standards”, listing “rigid application of opioid dosage thresholds” among the misapplications that harmed patients
- buprenorphine
- has no CDC factor at all, and that is a deliberate position rather than an omission. The page refuses rather than inventing one
- what no MME figure contains
- the reduction for incomplete cross-tolerance. CDC’s own caution adds that a new opioid is begun at a substantially lower dose than the calculated equivalent because of incomplete cross-tolerance and individual pharmacokinetic variability
Worked example
Oral tramadol, 400 mg a day — 100 mg four times a day
CDC 2022, factor 0.2: 400 × 0.2 = 80.00 MME a day
CDC pre-2022, factor 0.1: 400 × 0.1 = 40.00 MME a day
CDC 2022 ÷ CDC pre-2022 = 2.00-fold on one unchanged prescription, from one organisation's two tables
The consequence is not academic: 80 is above the 50 MME a day figure CDC's own decision support fires at and 40 is below it, so the same patient crosses that line or does not depending only on which CDC document the system was built from
Oral methadone 30 mg a day: 2022 returns 30 × 4.7 = 141.00; the pre-2022 band for 21 to 40 mg a day returns 30 × 8 = 240.00, a 1.70-fold gap
Oral methadone 80 mg a day: 2022 returns 376.00; the pre-2022 top band returns 80 × 12 = 960.00, a 2.55-fold gap. The pre-2022 figure rises faster than the dose because the band changes underneath it
A 50 micrograms an hour fentanyl patch: 50 × 2.4 = 120.00 MME a day on both CDC tables, which is the one row the two sets have never disagreed about
Morphine 60 mg a day returns 60.00 on both, because the scale is anchored on oral morphine
CDC’s two conversion factor tables, side by side
| Opioid | CDC 2022 guideline | CDC pre-2022 conversion file | Changed? |
|---|---|---|---|
| Morphine, oral | 1 | 1 | No |
| Codeine, oral | 0.15 | 0.15 | No |
| Hydrocodone, oral | 1 | 1 | No |
| Hydromorphone, oral | 5 | 4 | Yes — 1.25-fold |
| Oxycodone, oral | 1.5 | 1.5 | No |
| Oxymorphone, oral | 3 | 3 | No, but MSD’s table implies 2 for the same drug |
| Tapentadol, oral | 0.4 | not in the file | Added |
| Tramadol, oral | 0.2 | 0.1 | Yes — 2-fold |
| Methadone, oral | 4.7 flat | 4 from 1 to 20 mg a day, 8 from 21 to 40, 10 from 41 to 60, 12 at 61 and above | Yes — the dose-dependence was removed |
| Fentanyl, transdermal, per microgram an hour | 2.4 | 2.4 | No |
| Fentanyl, buccal, sublingual or lozenge, per microgram | not in the 2022 table | 0.13 | Dropped |
| Buprenorphine, any product | no factor | no factor | No calculation exists, by CDC’s stated position |
What guidance actually says at the MME figures it names
| Figure | Source | What the guidance says |
|---|---|---|
| 50 MME a day | CDC 2022 decision-support logic | The alert fires at 50 or more and offers documentation, a lower dose, a gradual change, or a snooze if benefits outweigh risks. Below 50 it says not to interrupt the clinician |
| 50 MME a day | CDC, Assess Risks of Opioid Use | Lists “Taking higher dosages of opioids (e.g., ≥50 MME/day)” among the circumstances in which to “Offer naloxone when prescribing opioids”. An offer, not a threshold for stopping |
| 50 MME a day | Maryland PDMP MME fact sheet, reproducing CDC | Extra precautions: monitor pain and function more frequently, and discuss dose reduction, tapering or discontinuation if benefits do not outweigh harms |
| 90 MME a day | CDC 2016 guideline, Recommendation 5 | Clinicians “should avoid increasing dosage to ≥90 MME/day or carefully justify” exceeding it. Withdrawn from the recommendation text in 2022 |
| 90 to 200 MME a day | CDC 2016 guideline, rationale | The evidence reviewed covered a “range of dosing thresholds of 90 MME/day to 200 MME/day”, which is the width of the uncertainty behind the single number |
| No figure at all | CDC 2022 guideline, Recommendation 4 | “carefully evaluate individual benefits and risks when considering increasing dosage” and “avoid increasing dosage above levels likely to yield diminishing returns in benefits relative to risks to patients”. The number is gone and the judgement is not delegated to arithmetic |
A surveillance construct, and what happens when it is used clinically
The morphine milligram equivalent is a United States regulatory and epidemiological construct. A daily opioid dose is multiplied by a conversion factor and the products are summed, producing one number per patient per day that can be aggregated across a state, compared between prescribers, written into a claims edit or used to define a cohort. CDC’s own archived description of the conversion file is that it was “intended solely for research, analytic purposes”, and CDC has discontinued updating it, naming the table in the 2022 guideline as its sole remaining resource on the subject.
Used for what it was built for, it works. Used on an individual, it is blind to almost everything that decides the answer. It cannot see that codeine and tramadol are prodrugs whose effect depends on CYP2D6 activity, so that the same milligram dose produces a large exposure in an ultrarapid metaboliser and almost none in a poor one. It cannot see tolerance, which is the difference between a dose that is routine and one that is fatal. It cannot see renal function, and therefore cannot see morphine-6-glucuronide accumulating. It cannot see formulation or route. And it cannot see the reduction for incomplete cross-tolerance, which is the step that prevents the overdose when an opioid is changed. CDC’s third published caution about its own table says the quiet part out loud: “Do not use the calculated dose in MMEs to determine the doses to use when converting one opioid to another.”
The 2022 guideline is also, in part, a correction of how the 2016 one was used. The 2016 recommendation told clinicians to “avoid increasing dosage to ≥90 MME/day or carefully justify” going further, and that number was widely reimplemented as a hard ceiling by payers, pharmacies and regulators. The 2022 guideline removes it from the recommendation text, replaces it with “avoid increasing dosage above levels likely to yield diminishing returns in benefits relative to risks to patients”, and states in its own introduction that it aims to discourage “the misapplication of opioid pain medication dosage thresholds as inflexible standards”, listing “rigid application of opioid dosage thresholds” among the misapplications that harmed patients. The 50 MME a day figure that survives in CDC’s decision-support logic asks for documentation, review and an offer of naloxone — not a refusal.
CDC also disagrees with itself on the arithmetic, which is this page’s reason for printing both columns. Hydromorphone moved from 4 to 5, tramadol from 0.1 to 0.2 and methadone from four dose-banded factors to a flat 4.7. These are population approximations; the published cross-tolerance reduction applies after any equivalence; your own formulary governs. The notes below set all three out in full. The United Kingdom equivalent of this figure, built on different factors, is on the oral morphine equivalent page.
Frequently asked questions
What is a morphine milligram equivalent?
A daily opioid dose multiplied by a published conversion factor relative to oral morphine, summed across a patient’s opioids. It is a surveillance and policy construct: CDC’s own archived description of its conversion file is that it was “intended solely for research, analytic purposes”. The arithmetic is the same as an oral morphine equivalent; the factors are not.
Why do CDC’s two factor tables disagree?
Because the 2022 guideline revised three rows. Hydromorphone went from 4 to 5, tramadol from 0.1 to 0.2, and methadone from four dose-banded factors — 4, 8, 10 and 12 — to a flat 4.7. MO HealthNet’s September 2023 notice records all three changes individually. At 80 mg of methadone a day the two CDC answers differ 2.55-fold, and for a patient on 400 mg of tramadol the gap is exactly twofold, which can move them across the 50 MME a day figure CDC’s own alert logic uses.
Is 50 or 90 MME a day a maximum?
Neither figure is a maximum in the document that publishes it. CDC’s 2022 decision support fires at 50 and offers documentation, review or a gradual change; its clinical guidance lists 50 MME a day among the reasons to offer naloxone. The 90 figure comes from the 2016 recommendation, which asked clinicians to avoid exceeding it or to justify doing so — and the 2022 guideline withdrew it, saying explicitly that it aims to discourage “the misapplication of opioid pain medication dosage thresholds as inflexible standards”.
Why is there no MME for buprenorphine?
Because CDC publishes none, as a position rather than an oversight. Maryland’s reproduction of the CDC factor set states it directly: “There is not a calculation to identify equivalency therefore MME is not available for buprenorphine products.” Buprenorphine is a high-affinity partial agonist with a ceiling on respiratory depression and it does not behave like a point on a potency scale. This page refuses rather than inventing a number.
Why does this page show no coloured band under the figure?
Because a coloured bar under a dose equivalence reads as a verdict on that dose, and no source on this page supports one. Every MME figure guidance names is a trigger for a conversation, a review or an offer of naloxone, not a pass-or-fail line — and rigid application of exactly these thresholds is what CDC’s 2022 guideline names as a cause of patient harm. The number is printed; the judgement is not simulated.
Related calculators
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(RR-3). Its conversion table, reproduced in CDC’s own 2022 Implementation Guide, reads: codeine 0.15, transdermal fentanyl 2.4 per microgram an hour, hydrocodone 1, hydromorphone 5, methadone 4.7, morphine 1, oxycodone 1.5, oxymorphone 3, tapentadol 0.4, tramadol 0.2. Of its seven cautions, the second is “Equianalgesic dose conversions are only estimates”, the third “Do not use the calculated dose in MMEs to determine the doses to use when converting one opioid to another”, and the seventh “These conversion factors should not be applied to dosage decisions related to the management of opioid use disorder”.
- CDC. Opioid National Drug Code and Oral MME Conversion File Update (archived). CDC has discontinued updating the file, describes it as “intended solely for research, analytic purposes”, names the 2022 guideline’s table as its “sole resource related to MME conversion factors”, and states: “Do not use the calculated dose in MMEs to determine the doses to use when converting one opioid to another.”
- CDC. 2022 CDC Clinical Practice Guideline for Prescribing Opioids Implementation Guide, ConversionFactors library. The pre-2022 factor set, read out of the library’s own CQL: codeine 0.15, hydrocodone 1, hydromorphone 4, morphine 1, oxycodone 1.5, oxymorphone 3, transdermal fentanyl 2.4 per microgram an hour, and methadone banded on the daily methadone dose — 4 from 1 to 20 mg a day, 8 from 21 to 40, 10 from 41 to 60, 12 at 61 and above. A dose below 1 mg a day returns a message rather than a factor.
- Maryland Department of Health, Prescription Drug Monitoring Program. MME Fact Sheet. Reproduces the pre-2022 CDC factor set row for row, adds buccal, sublingual and lozenge fentanyl at 0.13 per microgram, lists no factor for tramadol, and states of buprenorphine that “There is not a calculation to identify equivalency therefore MME is not available for buprenorphine products”. Used here as the independent corroboration of CDC’s own CQL library, which renders truncated. At 50 MME a day it advises monitoring pain and function more frequently and discussing dose reduction, tapering or discontinuation if benefits do not outweigh harms.
- MO HealthNet Division, Missouri Department of Social Services. Morphine Milligram Equivalent (MME) Factor Update for Hydromorphone, Methadone, and Tramadol, effective 17 September 2023, citing the CDC 2022 guideline. Records the three changes individually: hydromorphone 4 to 5, methadone 3 to 4.7, tramadol 0.1 to 0.2. The only document read for this batch that states the old and the new values side by side, which is what makes CDC’s disagreement with itself checkable rather than inferred.
- CDC. 2022 Implementation Guide, Recommendations 4 and 5. Recommendation 4: use caution “at any dosage”, “carefully evaluate individual benefits and risks when considering increasing dosage”, and “avoid increasing dosage above levels likely to yield diminishing returns in benefits relative to risks to patients”. Recommendation 5: “opioid therapy should not be discontinued abruptly” and clinicians “should not rapidly reduce opioid dosages from higher dosages”. The decision-support logic fires at “Patient Morphine Milligram Equivalent (MME) greater than or equal to 50” and then offers documentation and review, not a ceiling.
- CDC Guideline for Prescribing Opioids for Chronic Pain — United States, 2016. MMWR Recomm Rep. 2016;65(1). Recommendation 5, reproduced verbatim in the HL7 FHIR R4B PlanDefinition opioidcds-05 that CDC authored, said clinicians “should avoid increasing dosage to ≥90 MME/day or carefully justify a decision to titrate dosage to >90 MME/day”. Its rationale section describes the evidence as covering a “range of dosing thresholds of 90 MME/day to 200 MME/day”. Both numbers left the recommendation text in 2022.
- CDC Clinical Practice Guideline for Prescribing Opioids for Pain — United States, 2022. MMWR Recomm Rep. 2022;71(RR-3), introduction and rationale. It aims to discourage “the misapplication of opioid pain medication dosage thresholds as inflexible standards”, states that “Recommendations should not be applied as inflexible standards of care across patient populations”, and lists “rigid application of opioid dosage thresholds” among the misapplications that contributed to patient harm.
- CDC. Assess Risks of Opioid Use, clinical care guidance accompanying the 2022 guideline. Lists “Taking higher dosages of opioids (e.g., ≥50 MME/day)” among the circumstances in which to “Offer naloxone when prescribing opioids, particularly to patients at increased risk for overdose”. An offer, not a cut-off.
- MSD Manuals Professional Version. Equianalgesic Doses of Opioid Analgesics. Parenteral against oral: morphine 10 to 30 mg, codeine 130 to 200, hydromorphone 1.5 to 7.5, methadone 10 to 20, oxycodone 15 to 20, oxymorphone 1 to 15. Its footnotes state that the equivalences come from single-dose studies and clinical experience and are approximations; that on changing opioid the equianalgesic dose is cut by 50 per cent, and by 75 to 90 per cent for methadone; and that the morphine-to-methadone ratio is non-linear, rising from about 2:1 below 30 mg of oral morphine equivalent a day to about 20:1 at 1000 mg a day and above. Its oral oxymorphone figure of 15 mg against 30 mg of morphine implies a potency of 2, where CDC publishes 3.
Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/