Enter verified infusion details
Enter data exactly as documented. All fields use metric units. The page calculates values only after submission.
Example verification data
| Weight | Concentration | Pump rate | Calculated result |
|---|---|---|---|
| 50 kg | 20 mcg/mL | 2 mL/hr | 0.80 mcg/kg/hr |
| 80 kg | 10 mcg/mL | 4 mL/hr | 0.50 mcg/kg/hr |
These rows illustrate arithmetic only. They are not dosing recommendations or patient-specific instructions.
Formula Used
Concentration (mcg/mL) = total fentanyl (mcg) / final volume (mL)
mcg/kg/hr = concentration (mcg/mL) × pump rate (mL/hr) / weight (kg)
mL/hr = ordered mcg/kg/hr × weight (kg) / concentration (mcg/mL)
The page also divides mcg/kg/hr by 60 to show mcg/kg/min. Confirm which time unit your order and pump library require.
How to Use This Calculator
- Select the direction that matches your verification task.
- Enter a confirmed patient weight in kilograms.
- Enter the label concentration or calculate it from the prepared bag.
- Enter the documented pump rate or the verified ordered value.
- Review every result against the order, label, and smart pump library.
- Use local policy for independent checks, monitoring, and documentation.
Purpose and Safe Scope
This calculator converts a documented fentanyl pump rate into a weight-based hourly value. The reverse mode estimates a pump rate from a prescribed weight-based value. It does not select a dose. It does not replace a medication order. Use it only within an approved clinical workflow.
Fentanyl is a potent opioid. A small entry mistake can create a major clinical risk. Confirm the patient weight. Confirm whether the weight is current and recorded in kilograms. Confirm the prepared bag concentration from its pharmacy label. Confirm the programmed rate shown on the pump. Never infer the concentration from a vial strength alone.
Understanding the Units
mL/hr describes the volume delivered by an infusion device each hour. mcg/kg/hr describes drug exposure relative to body weight. Concentration links both measurements. It is written as micrograms per milliliter. A concentration of 20 mcg/mL means each milliliter contains 20 micrograms of fentanyl.
The calculator first determines micrograms delivered each hour. It then divides that hourly amount by weight in kilograms. The result is expressed in mcg/kg/hr. For reference, it also shows mcg/kg/min. It is not a recommended target.
Formula Used
Concentration equals total fentanyl in micrograms divided by final bag volume in milliliters. Hourly fentanyl equals concentration multiplied by pump rate. Weight-based hourly delivery equals hourly fentanyl divided by patient weight. Therefore, mcg/kg/hr equals concentration multiplied by mL/hr divided by kg.
The reverse calculation rearranges the same relationship. Pump rate equals prescribed mcg/kg/hr multiplied by kilograms divided by mcg/mL. Use the final prepared concentration. Do not use the drug amount before dilution unless the final volume is identical. Keep units visible during each verification.
How to Use This Calculator
Select the conversion direction. Enter the patient weight in kilograms. Then select the concentration source. Choose known concentration when the label already states mcg/mL. Choose prepared bag when you need the calculator to divide total fentanyl by final volume. Enter the pump rate for forward conversion. Enter the ordered weight-based value for reverse conversion.
Choose a display rounding option. Rounding changes presentation only. It never changes the underlying calculation. Review the result panel above the form. Compare the shown concentration, hourly fentanyl, pump rate, and weight-based value with the medication order and smart pump library. Record only values required by your local policy.
Checks Before Administration
Use this page as a secondary arithmetic check. Complete independent verification according to local policy. Match the bag label, medication order, patient identity, concentration, route, and pump channel. Confirm unit conventions. Some systems display mcg/kg/min rather than mcg/kg/hr. A sixty-fold unit error is possible when these values are confused.
Do not use this page for emergency decisions, dose escalation, or self-treatment. Monitor patients according to the ordered care plan and institutional procedure. For suspected over-sedation, respiratory compromise, wrong-programming, or infusion error, stop relying on the calculator and follow the facility emergency response process immediately.
Act promptly.
Frequently Asked Questions
1. What does mcg/kg/hr mean?
It describes micrograms of fentanyl delivered each hour for each kilogram of body weight. It is a weight-based expression. The calculator derives this value from the prepared concentration, pump rate, and confirmed weight.
2. What formula converts mL/hr to mcg/kg/hr?
Multiply concentration in mcg/mL by pump rate in mL/hr. Then divide by weight in kilograms. The calculation is: mcg/kg/hr = concentration × rate / weight.
3. Can this calculator determine concentration from a prepared bag?
Yes. Select the prepared bag option. Enter total fentanyl in micrograms and the final bag volume in milliliters. The calculator divides total drug by final volume to obtain mcg/mL.
4. Should I enter milligrams or micrograms for total fentanyl?
Enter micrograms. Convert milligrams before using the prepared bag option. One milligram equals 1,000 micrograms. Confirm the pharmacy label and your local unit conventions before entering any value.
5. Which patient weight should I use?
Use the weight specified by the active order or institutional protocol. The calculator cannot choose the correct clinical weight basis. Confirm the value is current, documented in kilograms, and appropriate for the order.
6. Why does final volume matter?
Final volume determines the prepared concentration. A bag containing the same drug amount can have different mcg/mL values when final volume changes. Use the final prepared volume, not the starting diluent volume.
7. Is mcg/kg/min the same as mcg/kg/hr?
No. They use different time units. Divide mcg/kg/hr by 60 to get mcg/kg/min. Multiply mcg/kg/min by 60 to get mcg/kg/hr. Confirm the unit used by the medication order and pump library.
8. Does this page recommend a fentanyl dose?
No. It performs unit conversion and arithmetic only. It does not recommend a starting value, titration step, clinical indication, or patient-specific treatment plan.
9. Can this page replace an independent double-check?
No. Use it as one arithmetic aid within your approved process. Follow local requirements for independent verification, medication labeling, smart pump use, patient monitoring, and documentation.
10. Why might my result look unexpected?
Check weight units, concentration units, final volume, decimal placement, and time units. Recheck the pump rate and the order. An unexpected result requires verification, not automatic acceptance.
11. What should I do if a medication error is suspected?
Do not rely on this calculator for emergency decisions. Follow your facility’s immediate response process, notify the responsible clinical team, and obtain urgent help for respiratory compromise or suspected overdose.