Opioid Equianalgesic Dose Conversion Calculator

Converts between opioid medications using equianalgesic ratios. Key conversions (oral morphine equivalents): morphine oral 30 mg = IV 10 mg; oxycodone oral 20 mg; hydromorphone oral 7.5 mg or IV 1.5 mg; fentanyl transdermal patch 25 mcg/h ≈ oral morphine 60 mg/day; methadone conversion is non-linear and requires specialist guidance. Reduce dose 25–50% when switching opioids (incomplete cross-tolerance).

Weight
Height
Clinical Guidance

BMI is a screening measure of body size, not a direct measure of body fat. The standard WHO categories are underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30).

BMI can overestimate body fat in athletes with high muscle mass and underestimate it in older adults with low muscle mass. Interpret it alongside waist circumference and clinical context rather than as a standalone diagnosis.

⚕ Clinical Disclaimer: These calculators are for educational and reference purposes only. Always verify results with qualified clinical judgment and current clinical guidelines. Do not use as a sole basis for medical decisions.
Advertisement

How It Works

Converts between opioid medications using equianalgesic ratios. Key conversions (oral morphine equivalents): morphine oral 30 mg = IV 10 mg; oxycodone oral 20 mg; hydromorphone oral 7.5 mg or IV 1.5 mg; fentanyl transdermal patch 25 mcg/h ≈ oral morphine 60 mg/day; methadone conversion is non-linear and requires specialist guidance. Reduce dose 25–50% when switching opioids (incomplete cross-tolerance)

Each component has a specific meaning:

  • Equianalgesic ratios — The equianalgesic ratios recorded for the scenario being assessed.

Note: Interpret the opioid conversion result against the thresholds and context described above.

How to Use

Enter the equianalgesic ratios for the scenario you are assessing. Converts between opioid medications using equianalgesic ratios. Key conversions (oral morphine equivalents): morphine oral 30 mg = IV 10 mg; oxycodone oral 20 mg; hydromorphone oral 7.5 mg or IV 1.5 mg; fentanyl transdermal patch 25 mcg/h ≈ oral morphine 60 mg/day; methadone conversion is non-linear and requires specialist guidance. Reduce dose 25–50% when switching opioids (incomplete cross-tolerance). Use the opioid conversion result to inform your calculation.

Related Calculators

Morphine PCA

Medical

Fentanyl ICU Infusion

Medical

Frequently Asked Questions