Opioid Dose Converter
Calculate approximate equianalgesic doses when switching opioids. Crucially: Because of incomplete cross-tolerance, the calculated new dose must routinely be reduced by 30-50% to prevent fatal respiratory depression.
High Risk Warning: Equianalgesic ratios are approximations based on single-dose studies. Patient response varies wildly. Always reduce the newly calculated dose by at least 30%, and titrate up cautiously.
Results (Total 24h Dose)
Raw Equianalgesic Dose (100%)
mg
Recommended Starting Dose (with % reduction)
mg / 24hrs
*Divide this total 24h dose by the appropriate dosing frequency for the preparation (e.g., divide by 2 for 12-hourly modified-release).
Equivalence Table
All doses approximate to 10mg Oral Morphine:
- Morphine (IV/SC) ~5mg
- Oxycodone (Oral) ~5mg - 6.6mg
- Oxycodone (IV/SC) ~5mg
- Codeine (Oral) ~100mg
- Tramadol (Oral) ~100mg
- Hydromorphone (Oral) ~1.3mg - 2mg
Source: Faculty of Pain Medicine (FPM) Guidelines. Note: Methadone and Fentanyl patches require highly specialized conversion tables and are excluded from this simple calculator.
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