Opioid Conversion Calculator

mg/day
Health

The Opioid Conversion Calculator estimates an equivalent daily dose when switching between opioids, via morphine milligram equivalents. It also suggests a reduced starting dose for incomplete cross-tolerance. For clinical education only.

Rates and fees change frequently. Always confirm the current figures with the official authority before relying on this result.

Formula

Equivalent dose = (From Dose × From Factor) ÷ To Factor; then reduce 25–50%
  • Both drugs are converted through morphine milligram equivalents.
  • Reduce the calculated dose by 25–50% for incomplete cross-tolerance when starting the new opioid.

Oxycodone 60 mg/day to morphine

Inputs
  • From Opioid: 1.5
  • Current Daily Dose: 60 mg/day
  • To Opioid: 1

60 × 1.5 = 90 MME; ÷ 1 = 90 mg morphine/day, start around 60 mg after reduction.

Frequently asked questions

Why reduce the dose when switching opioids?
Because cross-tolerance is incomplete — the new opioid can be more potent than expected, so starting lower improves safety.