Use this calculator to estimate the effective FiO_{2} that low flow oxygen
delivers.

Simply input the child's weight (in kg), his or her respiratory rate, the
current O_{2} flow rate and percent O_{2} at the blender.

Calculator Algorithm:

FiO_{2} = ((F x (B - 21) / 100)+(0.21 x R x W x 5.5)) / (R x W x 0.055)

The equation has four variables: weight in kg (W) , respiratory rate (R), gasflow (F) and percentage of oxygen in the gas (B).
We have modified Neil Finer's formula, Pediatr Pulmonol 1996;21(1):48-51 to allow for the use of an O_{2} blender.
A tidal volume of 5.5mL/kg is assumed.

Note that Neil Finer’s study looked at infants with weight ranging from approximately 600g to 4000g, so the calculator may be less valid outside that range.