IV Fluid Rate per Hour

Excel Formulas › Veterinary & Pet Care

All versions

IV fluids are ordered as a daily volume (often a maintenance rate per kg) and delivered as an hourly rate — and as drops per minute set on the line using the drip set factor.

Quick formula: hourly rate from a daily volume:
=daily_ml / 24
Total daily mL over 24 hours gives mL/hr. Times the drip factor over 60 gives drops per minute.

The example

1,440 mL/day.

AB
1ItemValue
21440 / 2460 mL/hr
3× 15 gtt / 60→ 15 gtt/min

The formula

The formula:

=daily_ml / 24 // daily volume ÷ 24

How it works

How it works:

  1. Compute the daily volume (e.g. maintenance mL/kg/day × weight).
  2. Divide by 24 for the hourly pump rate (mL/hr).
  3. For a gravity line: drops/min = mL/hr × drip_factor ÷ 60.
  4. The drip factor (gtt/mL) is printed on the IV set (e.g. 10, 15, 60).

Educational use only — not veterinary or medical advice. Dosing, fluid rates, and protocols must be set and verified by a licensed veterinarian for the individual patient. Always double-check against the drug label and a current formulary.

Try it: interactive demo

Live demo

Daily mL and drip factor (gtt/mL).

mL/hr · gtt/min

Variations

Drops per minute

Gravity set:

=ml_per_hour * drip_factor / 60

Maintenance daily volume

Per kg:

=ml_per_kg_per_day * weight_kg

Seconds per drop

For a slow rate:

=60 / drops_per_minute

Pitfalls & errors

Drip factor. Read gtt/mL off the IV set — 10/15/60 differ a lot.

mL/hr vs gtt/min. Pumps use mL/hr; gravity lines use drops/min.

Not advice. Fluid rates must be set by a veterinarian.

Practice workbook

📊
Download the free IV Fluid Rate per Hour practice workbook
An IV-rate sheet with the drops, maintenance, and seconds variants, plus 4 challenges with answers. No sign-up required.

Frequently asked questions

How do I calculate an IV fluid rate in Excel?
Divide the daily volume by 24: =daily_ml / 24 for mL/hr. 1,440 mL/day is 60 mL/hr.
How do I get drops per minute?
Multiply mL/hr by the drip factor over 60: =ml_per_hour * drip_factor / 60.
What's the drip factor?
The drops-per-mL of the IV set (10, 15, or 60 gtt/mL), printed on the package.

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Related formulas: IV drip rate · Constant rate infusion (CRI) · Drug dose by weight