The diet of the domesticated horse is influenced by both internal and external variables, such as age, breed, discipline, and workload, as well as the feed brand preference of the owner. With a range of products and feeds available to the horse owner, this has the potential to lead to inappropriate feeding management. The aim of this study was to evaluate the current mineral intakes of horses in the UK. An online questionnaire was used to collect data on horse and owner demographics and feed rations. Total daily intakes of phosphorus, calcium, sodium, and potassium were calculated based on forage, concentrate, and supplement information given in the questionnaire. Estimated mineral intakes were compared to recommended levels using a Wilcoxon signed-rank test. Intakes of phosphorus, calcium, sodium, and potassium were found to be significantly (P <.001) higher than NRC recommendations, with most estimated mineral intakes originating from the forage component of the diet. However, the calcium to phosphorus ratio was calculated at 2.07:1, which is close to the recommended ratio limits. Excess intakes of calcium, phosphorus, sodium, and potassium have the potential to influence the metabolism of additional macro and micro minerals and, therefore, further research into this area is recommended.