Morphine milligram equivalent (MME) calculator
Total daily MME across oral opioid prescriptions, for cumulative dose assessment only — not for switching opioids.
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This is a reference implementation of a published formula, provided for use by qualified healthcare professionals. It does not diagnose, does not account for the individual circumstances of any patient, and is not a recommendation for treatment. Confirm every result against your own institutional guidance before acting on it. Clinical judgement always takes precedence over a calculator.
About this calculation
Total daily morphine milligram equivalents express the combined dose of several opioid prescriptions on one scale, so that cumulative exposure can be assessed. This is a population-level risk-assessment measure. It is not an equianalgesic table and must not be used to convert a patient from one opioid to another.
Formula
Total MME/day = Σ (strength per dose × doses per day × conversion factor)
- Source
- CDC Clinical Practice Guideline for Prescribing Opioids for Pain — conversion factors for cumulative dose assessment (2022)
- Methodology version
- 1.0.0
- Last reviewed
- 2026-10-28
What this does not account for
- These factors are for assessing cumulative daily dose. They are NOT equianalgesic ratios and must not be used to switch a patient between opioids — doing so has caused fatal overdoses.
- Methadone and buprenorphine are deliberately excluded. Methadone’s relationship to morphine is non-linear and dose-dependent; buprenorphine is a partial agonist. The 2022 CDC guideline withdrew the simple factors for both.
- Transdermal fentanyl is excluded because it is dosed in micrograms per hour and its conversion is not a simple multiplication.
- Individual response varies widely with genetics, tolerance, organ function and interacting drugs. A given MME does not correspond to a given effect in a given person.
- MME thresholds in guidance are prompts to review, not limits requiring a dose reduction. Abrupt tapering carries its own serious risks.