This IV infusion rate calculator converts a mcg/kg/min drug order into a dose per minute and a pump rate in mL/hr, based on patient weight and drug concentration. This calculator is for educational/informational purposes only and is not a substitute for professional medical judgment.
Potent continuous infusions such as dopamine and dobutamine are usually ordered in micrograms per kilogram per minute, while infusion pumps are set in millilitres per hour. The calculator bridges the two in three steps:
Combined into one line: Rate (mL/hr) = Weight × Dose × 60 ÷ Concentration. Rearranged, the same relationship lets you check an infusion that is already running: Dose (mcg/kg/min) = Rate × Concentration ÷ (60 × Weight).
Infusions are prepared by adding a known amount of drug, usually in mg, to a known volume of fluid. Convert mg to mcg by multiplying by 1000, then divide by the total volume in mL.
| Drug added | Total volume | Working | Concentration |
|---|---|---|---|
| 400 mg | 250 mL | 400,000 ÷ 250 | 1600 mcg/mL |
| 200 mg | 250 mL | 200,000 ÷ 250 | 800 mcg/mL |
| 50 mg | 50 mL | 50,000 ÷ 50 | 1000 mcg/mL |
| 4 mg | 250 mL | 4,000 ÷ 250 | 16 mcg/mL |
These are arithmetic examples, not recommended dilutions. Use the concentration your hospital protocol or pharmacy label specifies, and include any volume already in the bag or syringe when you work it out.
A 70 kg patient is ordered 5 mcg/kg/min from a bag containing 400 mg in 250 mL (1600 mcg/mL). Dose per minute = 70 × 5 = 350 mcg/min. Dose per hour = 350 × 60 = 21,000 mcg/hr. Pump rate = 21,000 ÷ 1600 = 13.125 mL/hr, which the calculator displays as 13.125 and which would typically be programmed as 13.1 mL/hr on a pump that accepts one decimal place.
Because the rate rises in direct proportion to the dose, titrating up or down is easy to predict. For the same 70 kg patient and 1600 mcg/mL:
| Ordered dose (mcg/kg/min) | Dose (mcg/min) | Pump rate (mL/hr) |
|---|---|---|
| 2 | 140 | 5.25 |
| 5 | 350 | 13.125 |
| 10 | 700 | 26.25 |
| 15 | 1050 | 39.375 |
| 20 | 1400 | 52.5 |
Results are for learning and cross-checking only. Every infusion rate must be verified against the written order and the local protocol by a qualified healthcare professional before use.