Veterinary Fluid Calculator
Compute a maintenance fluid rate in mL per hour from body weight, a per-kilogram fluid rate in mL/kg/day, and the number of hours over which the total is delivered. This is a rate calculation only. It does not evaluate dehydration, ongoing losses or the appropriate fluid choice.
Formula
fluid rate (mL/hr) = body weight (kg) x rate (mL/kg/day) / hours total volume (mL) = fluid rate x hours
Worked example
A 10 kg patient at 60 mL/kg/day over 24 hours:
rate = 10 x 60 / 24 = 25 mL/hr
total = 25 x 24 = 600 mL
Common fluid rate values
| Species / situation | Typical rate |
|---|---|
| Adult dog maintenance | 40 to 60 mL/kg/day |
| Adult cat maintenance | 40 to 60 mL/kg/day |
| Puppy or kitten | 60 to 80 mL/kg/day |
Typical values for orientation only. Confirm the appropriate rate against a current reference and the individual patient.
What this does not do
- It does not include dehydration deficit or ongoing losses.
- It does not choose a fluid type or an additive.
- It does not adjust for cardiac or renal conditions.