Oxygen Flow Rate Calculator for Dogs and Cats
Calculate a starting flow-by or nasal cannula oxygen flow rate range based on patient weight, shown in both mL/min and L/min, for titration against the patient's actual response.
Body weight (kg)
Delivery method
Titrate to the patient, not the number
These are starting-point flow rates - always titrate to the patient's actual response (SpO2, respiratory effort, comfort) rather than fixing the flow at a calculated number and leaving it. Nasal cannula flows that feel too high often cause discomfort, sneezing, and gastric insufflation - if the patient seems uncomfortable, try the lower end of the range first and titrate up only as needed.
Oxygen cages are different
Flow needed depends on the specific cage's volume and how well it seals, not on patient weight. Follow your cage manufacturer's guidance and titrate the flow to achieve your target FiO2/SpO2 rather than using a weight-based formula.
How to use this tool
The formulas
Flow-by (blow-by) oxygen: 100-200 mL/kg/min. Nasal cannula (single nostril): 50-100 mL/kg/min. Flow-by is less efficient at delivering oxygen to the airway than a nasal cannula, so it generally needs a higher flow rate for the same effect.
Bilateral nasal cannulas
If using bilateral nasal cannulas, some references support combined flows up to roughly 150-200 mL/kg/min total, split between the two cannulas.
Always titrate
These are starting-point flow rates, not fixed targets. Titrate to the patient's actual response - SpO2, respiratory effort, and comfort - rather than leaving the flow fixed at a calculated number. Flows that feel too high, especially with a nasal cannula, often cause discomfort, sneezing, and gastric insufflation.
Oxygen cages
This calculator doesn't cover oxygen cages, since the flow needed depends on the specific cage's volume and how well it seals rather than on patient weight. Follow your cage manufacturer's guidance and titrate to your target FiO2/SpO2 instead.
Frequently asked questions
What's the difference between flow-by and nasal cannula oxygen delivery in terms of flow rate needed?
Flow-by/blow-by, where oxygen tubing is simply held near the patient's nose/mouth, is less efficient at delivering oxygen to the airway than a nasal cannula placed into the nostril, so it generally requires a higher flow rate - roughly 100-200 mL/kg/min - compared to a nasal cannula's roughly 50-100 mL/kg/min per nostril.
Why titrate the flow rate instead of just using the calculated number?
The calculated range is a starting point based on weight alone - the patient's actual oxygenation status (SpO2), comfort, and respiratory effort should guide adjustments up or down from there, since individual response varies.
What if a nasal cannula flow rate seems to be causing discomfort?
Try the lower end of the calculated range first; signs like sneezing, head-shaking, or reluctance can indicate the flow is too high for that individual - and nasal cannula oxygen at high flows can also cause gastric insufflation from swallowed gas.
Can this calculator tell me the flow rate for an oxygen cage?
No - oxygen cage flow requirements depend on the specific cage's volume and seal quality rather than patient weight, so there's no reliable weight-based formula for it; follow your cage's manufacturer guidance and titrate to your target FiO2/SpO2 instead.