To reduce the risk of development of dental fluorosis, total fluoride intake in infancy and early childhood should be monitored and examined for signs of excessive fluoride exposure. The urinary fluoride/creatinine ratio (UF/Cr) in a spot urine sample could be a useful systemic fluoride exposure monitoring tool; replacing 24h urine collection. However, there are no reference value for UF/Cr corresponding to excessive systemic fluoride exposure in children. In this study, we took 158 simultaneously collected total daily fluoride intake and excretion data in children <7 years from UK studies conducted by our team from 2002-2014. This study showed a strong positive linear relationship between total daily fluoride intake and UF/Cr, which suggests value in the use of a UF/Cr for estimation of fluoride intake in young children. This study has also established, for the first time, an upper reference value of a UF/Cr of 1.69 corresponding to excessive fluoride intake currently suggested as being >0.07 mg/kg bw/day.