Units per Hour Calculator: Heparin and Insulin Drips
Heparin, insulin, and other continuous drips are ordered per hour. Enter the bag (drug and volume) and either the ordered dose per hour or the pump rate.
Shows the work. Answer, formula, and numbered steps, rounded the way nursing exams expect. For study and exam practice, not for patient care.
Formula
mL/hr = ordered units/hr ÷ units per mL.
Fill in the fields and press Calculate to see the answer and every step.
For study and exam practice, not for patient care.
Rounding: Pump rates under 100 mL/hr round to the tenth; 100 mL/hr or more, to a whole number. Units/hr rounds to a whole unit.
Terms: Units, Concentration, mL/hr
Worked examples
Heparin 1,300 units/hr is ordered. The bag is heparin 12,500 units in 250 mL.
- Solve for
- Pump rate (mL/hr)
- Ordered dose per hour
- 1,300 units/hr
- Drug in the bag
- 12,500 units
- Bag volume
- 250 mL
Formula mL/hr = ordered units/hr ÷ units per mL.
- Concentration = 12,500 units ÷ 250 mL = 50 units/mL.
- mL/hr = 1,300 units/hr ÷ 50 units/mL = 26 mL/hr.
- 26 mL/hr is exact, so no rounding is needed.
Answer 26 mL/hr
A heparin infusion of 12,500 units in 250 mL is running at 20 mL/hr. How many units/hr is the client receiving?
- Solve for
- Dose per hour
- Pump rate
- 20 mL/hr
- Drug in the bag
- 12,500 units
- Bag volume
- 250 mL
Formula mL/hr = ordered units/hr ÷ units per mL.
- Concentration = 12,500 units ÷ 250 mL = 50 units/mL.
- units/hr = 20 mL/hr × 50 units/mL = 1,000 units/hr.
- 1,000 units/hr is exact, so no rounding is needed.
Answer 1,000 units/hr
FAQ
How do you calculate mL/hr from units/hr?
Find the concentration (units in the bag ÷ mL in the bag), then divide the ordered units/hr by it: mL/hr = units/hr ÷ units/mL.
How do you find units/hr from the pump rate?
Multiply the rate by the concentration: units/hr = mL/hr × units/mL.
Does this work for mg/hr drips?
Yes. Choose mg (or g, mcg, mEq) as the dose unit; the bag's drug amount is converted to the same unit first.