Morphine Equivalent Calculator
This morphine equivalent calculator converts one opioid dose into morphine milligram equivalents (MME) per day, the common scale clinicians use to compare opioid strength and judge overdose risk. Pick the drug, enter the dose per administration and how many times a day it is taken, and the tool multiplies dose by frequency by the CDC conversion factor for that drug. Read the safety section before using the number for anything: an MME total is a risk and comparison guide, not a dosing instruction, and it must never be used on its own to switch a patient from one opioid to another.
Total Daily MME
Note: This is for educational purposes only. Consult healthcare professionals for medical decisions. MME ≥ 50 mg/day increases overdose risk. Conversions are estimates: do not use this result to switch opioids without clinical judgment.
Quick Answer
Oxycodone 20 mg taken once a day converts at the CDC factor of 1.5, giving a total daily MME of 30.0 mg, inside the lower band below 50 MME/day. The calculator above is pre-filled with this exact case. Every factor it uses was checked line by line against the CDC 2022 table, and five factors carried by the older version of this page (hydrocodone, fentanyl patch, methadone, hydromorphone and tramadol) were corrected to the CDC values shown in the table below.
Key takeaways
- MME/day = dose per administration, times doses per day, times the drug’s CDC conversion factor.
- Caution rises at 50 MME/day; the CDC says avoid increasing to 90 MME/day or carefully justify it.
- A fentanyl patch is entered in mcg/hr with frequency 1: a 25 mcg/hr patch is 60 MME/day, not 2,500.
- Never use an MME figure alone to set a dose when switching opioids. Incomplete cross-tolerance means the new drug is normally started well below the calculated equivalent, by a clinician.
- Quick Answer
- How to use this morphine equivalent calculator
- The MME formula and the CDC conversion factors
- Worked examples, checked against the tool
- What the 50 and 90 MME bands actually mean
- Safety limits: what an MME number cannot do
- What competing calculators miss
- Frequently asked questions
- Add This Calculator to Your Website
- References
How to use this morphine equivalent calculator
Three entries produce the total: drug, dose per administration, and times per day. Follow the steps in order, because the two classic errors on this tool both come from the dose and frequency fields.
- Select the opioid. The list covers the nine drugs the CDC table and standard equianalgesic references support here, including oral and IV morphine as separate entries.
- Enter one dose, not the daily total. The field is labelled per administration on purpose: the tool multiplies by frequency itself. Entering the daily total and a frequency above 1 double-counts the drug.
- Enter the frequency. Twice-daily dosing is 2, four times a day is 4. For a fentanyl patch, leave it at 1 and enter the patch strength (12, 25, 50 mcg/hr and so on) in the dose field.
- Read the band, not just the number. The result shows the MME total to one decimal place and the risk band it falls in. A total near a boundary deserves the caution of the higher band.
If the patient takes more than one opioid, run each drug separately and add the MME totals together. That summed total is the figure the CDC thresholds apply to. For a worked check on a different drug family, the medicine dosage calculator covers weight and schedule based dosing, and the opioid calculator covers the wider opioid conversion picture.
The MME formula and the CDC conversion factors
Total daily MME = dose per administration × administrations per day × conversion factor. The factors below are the CDC Clinical Practice Guideline for Prescribing Opioids for Pain (2022) table, reproduced exactly, with one labelled exception: IV morphine is not in the CDC oral table, and its factor of 3 is the standard equianalgesic estimate (10 mg IV morphine is roughly equal to 30 mg oral morphine).
| Opioid | Dose unit | CDC factor | 10 units = MME/day |
|---|---|---|---|
| Morphine (oral) | mg | 1 | 10.0 |
| Morphine (IV, equianalgesic estimate) | mg | 3 | 30.0 |
| Oxycodone | mg | 1.5 | 15.0 |
| Hydromorphone | mg | 5 | 50.0 |
| Codeine | mg | 0.15 | 1.5 |
| Tramadol | mg | 0.2 | 2.0 |
| Hydrocodone | mg | 1 | 10.0 |
| Fentanyl transdermal | mcg/hr | 2.4 | 24.0 |
| Methadone | mg | 4.7 | 47.0 |
Two cautions from the CDC belong next to any factor table. First, these conversions are estimates and cannot account for individual differences in genetics and pharmacokinetics. Second, methadone and fentanyl deserve extra care: methadone has a long, variable half-life and its peak respiratory depressant effect arrives later and lasts longer than its pain relief, while fentanyl patch absorption changes with heat and skin conditions.
Worked examples, checked against the tool
Each row below was run through the calculator code itself, not worked out by hand and assumed. Enter the same dose and frequency and you will see the same result, to the same decimal place.
| Case | Math | Total daily MME | Band |
|---|---|---|---|
| Oxycodone 20 mg, once daily | 20 × 1 × 1.5 | 30.0 mg | Lower |
| Hydrocodone 10 mg, four times daily | 10 × 4 × 1 | 40.0 mg | Lower |
| Fentanyl patch 25 mcg/hr, frequency 1 | 25 × 1 × 2.4 | 60.0 mg | Moderate |
| Morphine (oral) 30 mg, twice daily | 30 × 2 × 1 | 60.0 mg | Moderate |
| Codeine 100 mg, once daily | 100 × 1 × 0.15 | 15.0 mg | Lower |
The hydrocodone row is the one to study. The older version of this page carried a factor of 0.25 for hydrocodone and reported this exact prescription as 10.0 MME, a quarter of the CDC figure. Anyone monitoring a patient against the 50 MME threshold with that factor would have seen a comfortable margin that does not exist.
What the 50 and 90 MME bands actually mean
The bands are action thresholds from the CDC guideline, not grades of safety. Risk exists at any dose and climbs as the total climbs; the bands mark where the guideline tells clinicians to change what they do.
Below 50
MME/day. The tool’s lower band. Prescribe the lowest effective dose and reassess regularly; lower does not mean risk-free.
50 to 89
MME/day. Carefully reassess benefits and risks before increasing, follow up more often, and consider offering naloxone.
90 and above
MME/day. The CDC says avoid increasing dosage to this level, or carefully justify the decision. Overdose risk is significantly higher.
One boundary detail matters: the tool places exactly 50 in the moderate band and exactly 90 in the high band, matching the guideline’s wording of ≥50 and ≥90. A total that lands on a boundary should be treated as being in the higher band, because that is how the guideline reads it.
Safety limits: what an MME number cannot do
An MME total supports risk assessment and comparison. It does not set doses, and treating it as a dosing instruction is the single most dangerous misuse of this tool.
- Do not use MME to switch opioids on your own. The CDC states plainly: do not use the calculated dose in MMEs to determine the doses to use when converting one opioid to another. Because of incomplete cross-tolerance, a clinician starting a new opioid typically prescribes substantially less than the calculated equivalent and titrates up.
- Do not use these factors for opioid use disorder treatment dosing. The CDC table is for pain management; buprenorphine products for pain are excluded from it entirely because partial agonists behave differently.
- Methadone needs a specialist. Its conversion is the least reliable on the list, its half-life varies widely between patients, and respiratory depression can peak after the analgesic effect fades.
- Fentanyl patches are for opioid-tolerant patients only, are never a starting opioid, and absorb faster with heat, fever or hot baths.
- The total ignores the patient. Age, kidney and liver function, sleep apnea, alcohol and sedative use all change real risk at the same MME number.
If a total surprises you, in either direction, that is a reason to talk to the prescriber or pharmacist, not to adjust a dose yourself. Never change, skip or supplement a prescribed opioid dose based on a calculator result.
What competing calculators miss
Most MME tools get the arithmetic right and the context wrong. Several still publish the superseded 2016 fact sheet factors (hydromorphone 4, tramadol 0.1, tiered methadone) without saying which CDC table they used, so two reputable-looking calculators can disagree by 25% on the same prescription. Many present a single converted dose with no statement that it must not be used to set a switching dose. Fentanyl is the recurring failure: tools that ask for a dose in mg invite users to enter a patch strength as if it were milligrams, and a few carry fentanyl factors orders of magnitude above the CDC’s 2.4 per mcg/hr. This page names its source table (CDC 2022), enters the patch in mcg/hr with the frequency locked by instruction to 1, prints the not-for-switching warning inside the result itself, and corrects the five stale or wrong factors its own earlier version carried.
Frequently asked questions
It is a standardised way to express an opioid dose as the amount of oral morphine with roughly the same strength. One milligram of oral morphine is 1 MME, oxycodone counts 1.5 MME per milligram, and codeine counts 0.15. Adding the MME of every opioid a patient takes gives one daily total that prescribers can compare against safety thresholds.
Multiply the dose in one administration by the number of administrations per day, then multiply by the drug’s CDC conversion factor. Oxycodone 20 mg taken twice a day is 20 times 2 times 1.5, which is 60 MME per day. If more than one opioid is taken, calculate each one the same way and add the results.
The CDC factor for hydrocodone is 1.0, the same as oral morphine, so 40 mg of hydrocodone per day is 40 MME per day. An earlier version of this page carried 0.25 for hydrocodone, which understated the total by a factor of four. That error has been corrected to the CDC 2022 value.
Select Fentanyl (transdermal mcg/hr), enter the patch strength in micrograms per hour in the dose field, and leave the frequency at 1. A 25 mcg/hr patch is 25 times 2.4, which is 60 MME per day. Do not enter the patch strength as milligrams and do not raise the frequency: the patch delivers continuously, so the strength already describes the full day.
Methadone builds up in the body over days, its half-life varies widely between patients, and its breathing-slowing effect can peak later and last longer than its pain relief. The CDC 2022 table gives a single conversion factor of 4.7, which this calculator uses, but any methadone dose change belongs with a clinician experienced with the drug, not with a calculator.
No. The CDC says the calculated MME dose must not be used to determine the dose of a new opioid. Because tolerance does not transfer completely between opioids, a clinician switching a patient starts the new drug substantially below the calculated equivalent and adjusts from there. Use this tool to understand and monitor a total, never to set a replacement dose yourself.
At 50 MME per day the CDC guideline calls for a careful reassessment of benefits and risks before any increase, more frequent follow-up, and considering naloxone. At 90 MME per day the guideline says to avoid increasing the dosage to that level or to carefully justify the decision, because overdose risk rises significantly. These are prompts for a clinical review, not automatic cut-offs for patients already stable on a dose.
No. It performs one arithmetic conversion using published CDC factors and shows which risk band the total falls in. It does not know the patient’s age, other medicines, kidney or liver function, sleep apnoea or history, all of which change real risk. Decisions about starting, changing or stopping an opioid belong with the prescriber and pharmacist who know that full picture.
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References
- Centers for Disease Control and Prevention. CDC Clinical Practice Guideline for Prescribing Opioids for Pain, United States, 2022 (MMWR Recommendations and Reports). Accessed October 22, 2026.
- Centers for Disease Control and Prevention. Clinical Care and Treatment of Pain (Overdose Prevention for Healthcare Providers). Accessed October 22, 2026.
- Centers for Disease Control and Prevention. Reversing an Opioid Overdose with Naloxone. Accessed October 22, 2026.
- Centers for Disease Control and Prevention. Understanding the Opioid Overdose Epidemic. Accessed October 22, 2026.
- National Institute on Drug Abuse. Prescription Opioids: DrugFacts. Accessed October 22, 2026.
- U.S. Food and Drug Administration. Opioid Medications: Information for Patients and Healthcare Professionals. Accessed October 22, 2026.
- Substance Abuse and Mental Health Services Administration. Treatment Options for Substance Use Disorders. Accessed October 22, 2026.
- Centers for Medicare and Medicaid Services. Opioids: CMS Key Initiatives. Accessed October 22, 2026.
- U.S. Department of Veterans Affairs and Department of Defense. VA/DoD Clinical Practice Guideline for Opioid Therapy for Chronic Pain. Accessed October 22, 2026.
- Dowell D, Ragan KR, Jones CM, Baldwin GT, Chou R. Prescribing Opioids for Pain: The New CDC Clinical Practice Guideline (New England Journal of Medicine summary, PMC). Accessed October 22, 2026.