This easy to use app calculates the adjusted serum Calcium for patients with low Albumin levels. Since the major part of Calcium in serum is attached to Albumin, the measred "total Calcium" should be adjusted accordingly. The formula used is the one described in Payne et al: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1587636/]. Data entry is very convenient due to the customized keyboard. Both mg/dL and mmol/L can be used for the measured Calcium level and both mg/dL and g/gL for the Albumin