What is a morphine milligram equivalent (MME)?

An MME (also called oral morphine equivalent, OME) expresses the potency of any opioid relative to 1 mg of oral morphine. For example, oxycodone has an MME factor of 1.5, so 10 mg oral oxycodone equals 15 MME. It is the standard unit used by the CDC and state prescription drug monitoring programs.

What MME thresholds does the CDC recommend?

The 2022 CDC Clinical Practice Guideline for Prescribing Opioids notes that the risk of overdose increases at doses ≥50 MME/day, and substantially increases at ≥90 MME/day. These are caution thresholds, not hard limits — individualized clinical assessment always applies.

Are the conversion factors the same for all routes?

No. Oral bioavailability differs by route. IV morphine is roughly three times more potent than oral morphine, giving it an MME factor of 3.0. Transdermal fentanyl is converted using the standard approximation of 2.4 mg oral morphine per mcg/hr patch dose per day.

Why is buprenorphine listed separately?

Sublingual buprenorphine has a ceiling effect and partial agonist activity that makes standard MME conversion imprecise. Common references assign 30 MME per 1 mg sublingual buprenorphine, but this is an approximation. High-dose buprenorphine formulations used for opioid use disorder are generally not compared using MME.

Can I add multiple opioids together?

Yes. Calculate the MME for each opioid separately, then sum them. The total daily MME is the aggregate load the CDC risk thresholds apply to. This calculator handles one drug at a time — add results manually for combination regimens.

Is this a substitute for clinical judgment?

No. This tool is for educational and reference purposes only. MME is a guide, not a prescription. Actual dosing decisions require individualized assessment of patient history, pain etiology, opioid tolerance, comorbidities, and current clinical guidelines. Always involve a qualified clinician.

Opioid Morphine Equivalent Calculator

Name: Opioid Morphine Equivalent Calculator
Availability: InStock
Author: Nham Vu

Enter any opioid and its daily dose to instantly calculate total morphine milligram equivalents (MME) and compare against CDC prescribing thresholds.

Opioid Dose Input

Opioid medication

Dose per administration

Doses per day

Select an opioid, enter the dose, and click Calculate MME.

Total Daily MME

0 MME / day

05090150+

Low Moderate ≥50 High ≥90

Calculation Breakdown

Drug —

Dose per admin —

Frequency —

MME conversion factor —

Formula —

Total daily MME —

CDC Prescribing Context

<50 MME/day — Lower risk range; standard caution applies.

50–89 MME/day — Increased overdose risk; CDC recommends careful reassessment.

≥90 MME/day — High risk; CDC 2022 guideline recommends avoiding or substantially reassessing.

Source: CDC Clinical Practice Guideline for Prescribing Opioids, 2022. Thresholds are risk indicators, not absolute limits.

Clinical disclaimer: This calculator is for educational and reference purposes only. MME values are approximations based on population-level equianalgesic data and do not account for individual opioid tolerance, genetics, comorbidities, or drug interactions. All dosing decisions must be made by a qualified clinician.

Summary

Enter any opioid and its daily dose to instantly calculate total morphine milligram equivalents (MME) and compare against CDC prescribing thresholds.

How it works

Select the opioid medication from the dropdown list.
Choose the route of administration (oral, transdermal, or IV/parenteral).
Enter the dose per administration in milligrams (or micrograms for fentanyl).
Enter how many times per day the medication is taken.
The calculator multiplies dose × frequency × the CDC MME conversion factor.
The total daily MME is displayed alongside CDC risk thresholds (50 and 90 MME/day).

Use cases

Assessing total daily opioid burden against CDC prescribing guideline thresholds.
Reviewing a patient's opioid regimen during medication reconciliation.
Educational reference for pharmacology students learning opioid potency.
Documenting MME in clinical notes for pain management consultations.
Calculating MME when adding a new opioid to an existing regimen.
Quick reference during palliative care or hospice dose reviews.
Comparing relative potency of different opioids prescribed simultaneously.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu