Use this calculator to estimate the effective FiO2 that low flow oxygen
Simply input the child's weight (in kg), his or her respiratory rate, the
current O2 flow rate and percent O2 at the blender.
FiO2 = ((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 O2 blender.
A tidal volume of 5.5mL/kg is assumed.
Note that Neil Finerís study looked at infants with weight ranging from approximately 600g to 4000g, so the calculator may be less valid outside that range.