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Infusion Time Calculator

Find how long a volume will take to infuse at a rate in mL/hr, shown in hours and minutes.

Infusion Time Calculator

Volume (mL) ÷ Rate (mL/hr) = Time (hr)

The volume in the bag or ordered.

Unit: mL

The ordered or programmed rate.

Unit: mL/hr

Calculated in your browser. Values are not saved or sent anywhere.

Infusion time

Enter the volume and the rate in mL/hr, then select Calculate.

Example: 500 mL ÷ 75 mL/hr = 6 hr 40 min

Educational Use & Safety

Educational and calculation use only. Dosage Calcs performs mathematical calculations using the values you enter. It does not determine whether a medication, dose, route, frequency, concentration, or infusion rate is appropriate or safe for a patient. Always verify medication orders, calculations, product labeling, and applicable clinical or institutional policies before medication administration. When in doubt, consult an appropriate licensed healthcare professional or pharmacist.

Educational Use & Safety

Educational use: You supply the volume and rate. This tool calculates duration only and does not judge whether a rate is appropriate. Learn more.

What this calculates

Given a volume and the rate it runs at, the infusion time is how long it will take to finish. This page gives the duration only, not the clock time it will end.

Formula and inputs

Volume (mL) ÷ Rate (mL/hr) = Time (hr)

  • Volume — the amount to infuse, in mL.
  • Rate — in mL/hr, as set on the pump or written in the order.

Converting decimal hours to minutes

The division often gives a decimal, such as 6.67 hours. That is not 6 hours 67 minutes. Keep the whole hours, then multiply only the decimal part by 60 to get minutes.

0.666… hr × 60 = 40 min

Worked examples

Example 1: hours and minutes

500 mL ÷ 75 mL/hr ≈ 6.6667 hr

Whole hours: 6 · 0.6667 hr × 60 = 40 min

= 6 hr 40 min

Example 2: whole hours

1,000 mL ÷ 125 mL/hr = 8 hr

Example 3: less than an hour

100 mL ÷ 200 mL/hr = 0.5 hr = 30 min

Rounding

The exact time is calculated first. Only the final total is rounded to the nearest whole minute. If that rounding reaches 60 minutes, it becomes one more hour, so you will never see "6 hr 60 min". Very short times that round to zero are shown as "less than 1 min".

Common mistakes

  • Reading 6.67 hr as 6 hr 67 min. Multiply the decimal part by 60.
  • Dividing the rate by the volume instead of the volume by the rate.
  • Using a drip rate in gtt/min. Convert to mL/hr first, or use the drip rate calculator.

What this tool does not do

It does not calculate an end time and does not assess whether the rate is appropriate.

FAQ

Can it tell me what time the infusion will finish?

No. To find the finish time, add the calculated duration to your start time by hand.

What rate should I use?

The rate comes from the order or pump. If you only know the volume and time, the IV flow rate calculator gives mL/hr.

Sources

Formulas, units, and terminology were checked against these open references. Wording on this page is our own.

All sources · How we build and test calculators