MME Calculator (Educational Use)
Excludes methadone, buprenorphine, and transdermal fentanyl because conversion requires specialized rules.
What is an opiate equivalency calculator?
An opiate (opioid) equivalency calculator estimates how strong one opioid regimen is compared with another by converting doses into Morphine Milligram Equivalents (MME). MME gives a common reference point so clinicians can discuss risk, evaluate total opioid exposure, and plan safer transitions.
While people often say "opiate," many prescriptions are technically "opioids." In everyday use, both terms are commonly used. This page keeps the term from the title while using opioid safety terminology throughout.
How this calculator works
The formula in this tool is:
MME/day = (dose per administration in mg) × (administrations per day) × (drug-specific conversion factor)
After estimating MME/day, the calculator also shows approximate equivalent daily doses for other oral opioids. It additionally displays a conservative reduced range (25% to 50% lower) often discussed when rotating opioids due to incomplete cross-tolerance.
Included conversion factors
- Morphine: 1
- Hydrocodone: 1
- Oxycodone: 1.5
- Hydromorphone: 4
- Oxymorphone: 3
- Codeine: 0.15
- Tramadol: 0.1
- Tapentadol: 0.4
Why MME matters
Total opioid exposure is associated with overdose risk, sedation, respiratory depression, falls, and other complications. MME is not a perfect predictor of harm, but it helps compare regimens and identify situations that need additional caution, especially at higher daily totals.
Important limitations
- Equianalgesic tables are estimates and vary by source.
- Patient factors (age, kidney/liver function, opioid tolerance, genetics) change real-world effects.
- Methadone and fentanyl conversions are nonlinear/specialized and not included here.
- Buprenorphine has unique pharmacology and should not be converted with simple MME math.
- Dose conversions are not prescriptions and do not replace clinician judgment.
Safer interpretation checklist
Use this output as a starting point, not an endpoint
If you are a patient, do not adjust medications on your own. If you are a clinician-in-training, use results for supervised decision-making only.
- Confirm formulation (immediate-release vs extended-release).
- Verify units and dosing frequency.
- Assess sedation risk and concurrent CNS depressants.
- Review renal/hepatic function and drug interactions.
- Plan close follow-up after any dose change.
Example
Suppose someone takes oxycodone 10 mg, four times daily. Daily oxycodone = 40 mg/day. With a factor of 1.5, the estimated total is 60 MME/day. That MME can then be translated into approximate daily equivalents of other oral opioids for discussion and taper/rotation planning.
Bottom line
An opiate equivalency calculator is useful for standardizing comparisons, but safe prescribing requires clinical context, careful monitoring, and individualized treatment goals. If you have concerns about opioid therapy, speak with a licensed clinician or pharmacist.