Infusion Rate Calculator

Calculate IV infusion rates in mL/hr or gtt/min from volume, time, drop factor, dose, concentration, and patient weight for pump or gravity drips.

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Infusion Rate Calculator Guide

This calculator helps with three common infusion tasks: standard IV pump rates, gravity drip rates, and dose-based medication infusions. Use consistent units, leave only the field you want solved blank, and verify the final setting before administration.

Core Formulas

Rate_{mL/hr} = \frac{Volume_{mL}}{Time_{hr}}

Volume_{mL} = Rate_{mL/hr} \times Time_{hr}

Time_{hr} = \frac{Volume_{mL}}{Rate_{mL/hr}}

gtt/min = \frac{Volume_{mL} \times DropFactor_{gtt/mL}}{Time_{min}}

gtt/min = \frac{Rate_{mL/hr} \times DropFactor_{gtt/mL}}{60}

How to Use Each Mode

Drop Factor Reference

Dose-Based Infusion Setup

For medication infusions, first determine the concentration in the bag or syringe, then convert the ordered dose into a pump rate.

Concentration_{mg/mL} = \frac{Drug_{mg}}{Volume_{mL}}

Concentration_{mcg/mL} = \frac{Drug_{mg} \times 1000}{Volume_{mL}}

mL/hr = \frac{Dose_{mcg/kg/min} \times Weight_{kg} \times 60}{Concentration_{mcg/mL}}

mL/hr = \frac{Dose_{mcg/kg/hr} \times Weight_{kg}}{Concentration_{mcg/mL}}

mL/hr = \frac{Dose_{mg/kg/hr} \times Weight_{kg}}{Concentration_{mg/mL}}

mL/hr = \frac{Dose_{mg/hr}}{Concentration_{mg/mL}}

Quick Unit Conversions

Examples

Common Mistakes to Avoid

• Mixing hours and minutes in the same calculation.
• Using the wrong drop factor for the tubing set.
• Forgetting to convert mg to mcg for orders written in micrograms.
• Entering total drug amount without dividing by bag volume to get concentration.
• Failing to round manual drip rates to whole drops per minute.
• Programming a pump in mL/min when the intended unit is mL/hr.

Input Checklist

Tip: If you are solving for a missing value in standard infusion mode, enter the two known values and leave only one field blank. For dose-based infusions, calculate or verify the concentration first, then convert the ordered dose to mL/hr.