IV Infusion Time Calculator

Work out iv infusion time instantly with clear inputs, formula shown and shareable results.

About IV Infusion Time Calculator

Divides the bag volume by the pump rate to give the infusion duration, and shows the matching gravity drip rate.

Formula

Infusion time

Time (h) = volume (mL) / rate (mL/h); drops per minute = volume x 20 / minutes on a standard set

Worked example

With the default values below, IV Infusion Time Calculator returns Infusion time of 8h. Change any input above and every figure here is recalculated in your browser.

Inputs used

Volume to infuseaccepts 10–5,000 mL: 1,000 mL
Pump rateaccepts 1–999 mL/h: 125 mL/h

Results

Infusion time: 8h
Time in hours: 8.00 h
Drip rate on a 20 drops/mL set: 41.7 drops/min

Step by step

1Values used
2Infusion time
3Infusion time= 480
4Time in hours= 8.00 h
5Drip rate on a 20 drops/mL set= 41.7 drops/min

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

Does the line prime count?

Priming volume is drawn from the bag, so the usable volume is slightly less than the labelled volume.

What if the rate changes mid-infusion?

Calculate each segment separately and add the times together.