Concentration-to-Rate

Convert between drug concentration, weight-based dose, and infusion rate.

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Dose value
0.1
Dose unit
mcg/kg/min
Patient weight
70 kg
Concentration value
0.064
Concentration unit
mg/mL

Result: Norepi at 0.1 mcg/kg/min, 70 kg, 64 mcg/mL: ~6.56 mL/hr

The tool opens with these values already filled in. Replace them with your own.

What you enter

  • Dose value
  • Dose unit
  • Patient weight (if dose per kg)
  • Concentration value
  • Concentration unit

What this is

Given any three of (drug amount in the bag, diluent volume, patient weight, target dose in mcg/kg/min or units/hr, pump rate in mL/hr), Sophie Well solves for the missing fourth and shows the working concentration in mcg/mL alongside the resulting pump rate. The same engine handles continuous infusions (vasopressors, sedatives, heparin) and bolus-then-maintenance presentations.

When to use it

Use this when a code-cart vasopressor bag has a non-standard concentration, when converting a literature dose (mcg/kg/min) into a pump rate at the bag concentration actually hanging at the bedside, or when reconciling a reported pump rate against the prescribed dose during handoff. The math is deterministic; the safety question is whether the unit selection (mcg vs units, /kg vs flat, /min vs /hr) matches the protocol you intend - the tool labels every step so a second reader can audit before the bag goes up.

How this is calculated

Standard infusion math: rate (mL/hr) = (dose per minute / concentration per mL) * 60. Bag presets per common institutional protocols.

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.