OBJECTIVES: To build an Excel calculator, taking demographic and clinical characteristics of rheumatoid arthritis (RA) patients in Turkey, and estimate the annual healthcare costs.  METHODS: 2009-2011 data from MEDULA, the Turkish national health insurance database, was used for the study. RA patients (ages 18-99) were identified for the identification period (June 1, 2010 - December 31, 2010) using International Classification of Disease Tenth Revision Clinical Modification (ICD-10-CM) codes. Patients were grouped as prevalent and incident cases and required to have two RA diagnoses at least 60 days apart. In order to estimate risk-adjusted total annual costs for prevalent and incident cases, generalized linear models (GLMs) were used. Patients' demographic and clinical characteristics were factors to determine the expected annual cost value, with coefficients of the characteristics built in the Excel calculator. A marginal effects table was created after GLM estimation by using such calculation. RESULTS: A total of 2,613 patients met all inclusion criteria, of which 693 were incident and 1,920 prevalent cases. Patients' demographic and clinical characteristics were entered into the Excel calculator. Risk-adjusted annual total costs were calculated at €2,021 for prevalent cases and €1,818 for incident cases.  The most expensive contributor to annual expenditures was prior biologic use for both groups. Prevalent patients who were prescribed disease-modifying anti-rheumatic drugs (DMARDs) in the baseline period incurred €5,898 more costs than those who were not. For incident cases, male patients incurred lower costs (€1,818 - €708 = €1,110), whereas respiratory comorbid conditions increased the total expected healthcare cost of incident RA patients by €916 (€1,818 + €916 = €2,734).  CONCLUSIONS: In outcomes research, an Excel calculator serves as an important tool to estimate and compare RA-related healthcare costs.