Enfamil A.R. Powder, 1820 calories per 12.9 oz. can. Enfamil A.R. is a 20 Cal/fl oz, thickened, milk-based infant formula that reduces spit-up in 1 week and is appropriate for the first 12 months. Enfamil A.R. is clinically proven to reduce frequency and volume of regurgitation and meets the reflux reduction guidance of the American Academy of Pediatrics.