Morphine Equivalent Dose Calculator
Morphine milligram equivalents (MME) convert different opioid doses to a common unit based on equianalgesic potency relative to oral morphine. The formula is: MME = Daily dose (mg) x MME conversion factor. The CDC 2022 Clinical Practice Guideline for Prescribing Opioids for Pain recommends careful risk assessment at doses of 50 MME/day or more, and avoiding or carefully justifying doses at or above 90 MME/day in chronic pain management. This calculator applies published CDC MME conversion factors.
MME conversion formula
Daily MME = Daily dose (mg) x MME conversion factor
MME conversion factors (CDC 2022): Codeine 0.15, Hydrocodone 1.0, Morphine 1.0, Oxycodone 1.5, Hydromorphone 5.0, Oxymorphone 10.0, Tramadol 0.1. Methadone and fentanyl have complex conversions requiring specialist input. These factors are for oral dosing unless otherwise specified.
CDC MME risk tiers (chronic pain context)
- Below 50 MME/day: lower risk; still requires clinical oversight and monitoring for all patients.
- 50 to 89 MME/day: increased risk; CDC recommends review of pain management plan and careful monitoring.
- 90 MME/day or more: substantially increased risk; CDC recommends avoiding unless benefits clearly outweigh risk, and expert review.
- Methadone conversions are dose-dependent and require specialist pharmacist or pain specialist input.
- These thresholds apply to chronic pain management; acute pain and cancer pain have different considerations.
MME calculator: frequently asked questions
What are morphine milligram equivalents (MME)?
Morphine milligram equivalents (MME) is a standardized unit that converts different opioid doses to an equivalent dose of morphine, allowing comparison of opioid potency across different agents. It enables assessment of total opioid burden and risk stratification.
Why is the MME threshold important?
The CDC Clinical Practice Guideline (2022) notes that overdose risk increases substantially above 50 MME/day and recommends avoiding or carefully justifying doses at or above 90 MME/day for patients with chronic pain. MME thresholds are also used in state prescription drug monitoring programs.
What are the standard MME conversion factors?
Codeine: 0.15; Hydrocodone: 1.0; Oxycodone: 1.5; Hydromorphone: 5.0; Morphine: 1.0; Fentanyl transdermal patch mcg/hr: multiply by 2.4 per day; Methadone: conversion varies by dose (3 to 12 or higher). These factors are from the CDC Opioid Prescribing Guideline.
Does this calculator account for fentanyl patches?
This calculator uses daily oral equivalents. For fentanyl transdermal patches: the CDC conversion is mcg/hr x 2.4 = daily oral MME. Enter that converted value. Always verify with current prescribing resources, as conversions for fentanyl and methadone have significant caveats.
Can this calculator be used for clinical prescribing decisions?
No. This tool is for educational and informational purposes only. MME calculations for actual patient care must be performed by a licensed healthcare professional using current clinical guidelines and validated clinical resources. Opioid prescribing requires comprehensive patient assessment.
Official sources
- Centers for Disease Control and Prevention: CDC Clinical Practice Guideline for Prescribing Opioids for Pain (2022).
- U.S. Food and Drug Administration: FDA Opioid Medications Information.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.