Vasopressor Dose Calculator

kg
mg
mL
mcg/kg/min
This calculator is an educational reference only. It does not replace clinical judgment, institutional protocols, or a prescriber’s orders. Always double-check the concentration and rate independently before starting or titrating a vasoactive infusion.

What is Vasopressor Dose Calculator

A vasopressor dose calculator converts between a weight-based dose (mcg/kg/min) and an infusion pump rate (mL/h) for drugs such as norepinephrine, dopamine, and dobutamine. It first works out the bag concentration from the drug amount (mg) and the diluent volume (mL), then uses the patient's weight to translate one value into the other. The rate is dose times weight times 60, divided by the concentration in mcg/mL.

How to use

  1. Choose the direction: Dose to Rate, or Rate to Dose.
  2. Enter the patient's weight in kilograms.
  3. Enter the drug amount in mg and the bag volume in mL to set the concentration.
  4. Enter the dose (mcg/kg/min) or the pump rate (mL/h) and read the converted value.

When to use it

You mix 4 mg of norepinephrine in 250 mL and want 0.1 mcg/kg/min for a 70 kg patient. Enter those numbers and you get 26.25 mL/h on the pump, at a concentration of 16 mcg/mL. Switch direction to check what dose a given rate is actually delivering when you titrate.

Frequently asked questions

What is the formula for a vasopressor infusion rate?

Rate (mL/h) = dose (mcg/kg/min) × weight (kg) × 60 ÷ concentration (mcg/mL). For 0.1 mcg/kg/min, 70 kg, and 16 mcg/mL, that is 0.1 × 70 × 60 ÷ 16 = 26.25 mL/h.

Which drugs is this calculator for?

Any weight-based continuous infusion dosed in mcg/kg/min, such as norepinephrine, epinephrine, dopamine, and dobutamine. Always follow your unit's standard concentration and protocol.

How is the concentration calculated?

Concentration (mcg/mL) = drug amount (mg) × 1000 ÷ bag volume (mL). For example, 4 mg in 250 mL is 4000 mcg ÷ 250 = 16 mcg/mL.

Can I share this tool with my inputs pre-filled?

Yes. The URL updates automatically as you type. Copy it from the address bar or use the Share button — anyone who opens the link will see your exact inputs ready to go.

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