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Opioid MME Converter

Calculate oral morphine milligram equivalents (MME) for common opioids. Used to standardize opioid dosing and assess risk thresholds per CDC guidelines.

Inputs

Opioid Conversion factor to oral morphine equivalents.

Dose per administration mg (or µg/hr for fentanyl patch)

Doses per day Number of administrations per 24 hours. Use 1 for fentanyl patch.

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Enter dose above.

Daily dose—

Risk assessment—

⚠ Critical safety note: Opioid conversions are estimates. Always reduce calculated equianalgesic doses by 25–50% for incomplete cross-tolerance when rotating between opioids. These factors should not be used for fentanyl patch → other opioid conversions directly.

CDC conversion factors (to oral morphine)

Codeine 200 mg oral = 30 mg morphine oral (×0.15)
Hydrocodone oral: ×1
Hydromorphone oral: ×4
Methadone oral: ×4–10+ (dose-dependent, highly variable — use caution)
Morphine oral: ×1 (reference)
Oxycodone oral: ×1.5
Oxymorphone oral: ×3
Tramadol oral: ×0.1
Tapentadol oral: ×0.1
Fentanyl patch (µg/hr): multiply by 2.4 for daily MME

CDC risk thresholds

≥ 50 MME/day: Increased risk — reassess and consider non-opioid alternatives
≥ 90 MME/day: Substantial risk — avoid or carefully justify; consider referral to pain specialist

Clinical pearls

Methadone conversion is non-linear and dose-dependent — higher doses have disproportionately higher potency. Consult a pain or addiction specialist.
Always account for incomplete cross-tolerance (reduce by 25–50%) when switching opioids.
Fentanyl patches take 12–24 hours to reach steady state; do not use these calculations for acute titration.
Consider naloxone co-prescribing at ≥ 50 MME/day.

References

CDC. Calculating Total Daily Dose of Opioids for Safer Dosage. 2022.
Dowell D, et al. CDC Clinical Practice Guideline for Prescribing Opioids for Pain. MMWR. 2022;71(3):1–95.