Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
Total daily MME
60.0
Risk screening category
Elevated — reassess, consider naloxone
Conservative rotation target (50% reduction)
30.0
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How to use this
- 1Enter opioid.
- 2Enter dose per administration (mg (mcg/hr for patch)).
- 3Enter administrations per day (use 1 for patch).
- 4Read your total daily mme on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Morphine milligram equivalents (MME) standardize different opioids and routes into one comparable daily dose so prescribers can screen for overdose risk and comply with prescribing guidelines. The CDC and most state prescription drug monitoring programs flag total daily MME at or above 50 as a point to reassess necessity and consider naloxone co-prescribing, and 90 MME/day or higher as a threshold associated with substantially higher overdose risk, generally avoided without careful justification and specialist involvement. Conversion factors vary by opioid and are approximations, not exact pharmacologic equivalence, because incomplete cross-tolerance between opioids means switching drugs at a calculated "equivalent" dose can still cause under- or overdosing — most guidelines recommend reducing the calculated equivalent dose by 25-50% when rotating opioids. This tool sums the MME contribution of up to several concurrent opioids using standard published conversion factors. It does not include tramadol, methadone (nonlinear conversion), or buprenorphine, which need specialist-level conversion. This tool is for education and workflow support only — not medical advice. Always verify results with a clinician and use clinical judgment alongside your institution's protocols.
Worked example
Using the values the calculator loads with:
Inputs
- Opioid: Oxycodone — factor 1.5
- Dose per administration: 10 mg (mcg/hr for patch)
- Administrations per day (use 1 for patch): 4
Results
- Total daily MME: 60
- Risk screening category: Elevated — reassess, consider naloxone
- Conservative rotation target (50% reduction): 30
What each field means
Inputs
- Opioid
- Pick the option that matches your situation — the maths changes per option. Choices: Morphine (oral) — factor 1, Oxycodone — factor 1.5, Hydrocodone — factor 1, Hydromorphone (oral) — factor 4, Codeine — factor 0.15, Fentanyl transdermal (mcg/hr) — factor 2.4/day, Tapentadol — factor 0.4.
- Dose per administration (mg (mcg/hr for patch))
- The dose per administration used in the calculation, measured in mg (mcg/hr for patch). Starts at 10 mg (mcg/hr for patch) so you have a working example on load.
- Administrations per day (use 1 for patch)
- The administrations per day (use 1 for patch) used in the calculation. Starts at 4 so you have a working example on load. Accepted range: 0–12.
Results
- Total daily MME
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Risk screening category
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Conservative rotation target (50% reduction)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What MME threshold should trigger extra caution?
CDC guidance identifies 50 MME/day as a point to reassess the benefits and risks, and to consider offering naloxone. At 90 MME/day or above, avoid increasing dose without careful reassessment and consider specialist consultation — overdose risk rises sharply at and above this range, especially with concurrent benzodiazepines.
Why reduce the dose when rotating opioids?
Cross-tolerance between different opioids is incomplete, meaning a patient tolerant to one opioid is not necessarily equally tolerant to another at the calculated equivalent dose. Most rotation protocols reduce the calculated new-drug MME by 25-50% initially and titrate up based on response, to avoid an unintentional overdose during the switch.
Why isn't methadone included in this calculator?
Methadone's conversion ratio to morphine is nonlinear — it gets disproportionately more potent at higher morphine-equivalent doses due to its long and variable half-life and different receptor pharmacology. Standard linear MME tables underestimate methadone's potency at high doses, so specialist-guided conversion tables or a pain/palliative consult are needed.
Does MME account for benzodiazepine or alcohol use?
No, MME is opioid-dose-only. Concurrent benzodiazepines, alcohol, or other sedatives multiply respiratory depression risk independent of the MME number, so a 'moderate' MME with concurrent sedative use can carry high real-world overdose risk that this calculator does not capture.
Accuracy and limitations
- Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
- Results do not account for medical conditions, medication, or pregnancy.
- Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Opioid Morphine Milligram Equivalent (MME) Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/opioid-morphine-equivalent
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/opioid-morphine-equivalent" target="_blank" rel="noopener">Opioid Morphine Milligram Equivalent (MME) Calculator — RevenueLab</a> (2026).</p>
Source: [Opioid Morphine Milligram Equivalent (MME) Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/opioid-morphine-equivalent) (2026).