A calcium determination method for lime mortars in old church ruins is described. Two volumetric analysis methods were employed: titration using EDTA solution, and with KMnO4 solution. The binder fraction with sieve size (<0.075mm) was used for titration which is abundant in CaCO3 as established by Fourier-Transform Infrared Spectroscopy (FTIR) technique. The mortar sample from Misamis Oriental yields a mean calcium concentration of 59.60% ± 4.64 and 60.48% ± 6.68 for EDTA and KMnO4, respectively, while the Metro Manila mortar sample is 73.54% ± 2.68 for EDTA and 73.33% ± 6.88 for KMnO4. Two tailed t-test and F-test analysis confirm that there is no statistical difference between EDTA and KMnO4 methods in determining the calcium content. Atomic Absorption Spectroscopy (AAS) technique validated the mean concentration values obtained from each method with less than 6.4% difference. The proposed titration methods are simple, rapid and sufficiently precise, without the use of expensive analytical instruments. This study is a good alternative method to easily determine the amount of calcium in historic lime mortars which is valuable in heritage conservation work and restoration of old structures in the Philippines. © 2017, Malaysian Society of Analytical Sciences. All rights reserved.