Religious expenditures are common to across all divine religions. Estimating the religious expenditure function of households and its share of total expenditures not only reveals the outcomes of past policies but also serves as a roadmap for governmental microeconomic policymaking and a valuable resource for private sector decision-making. This study estimates the religious expenditure function of Iranian households by distinguishing between urban and rural areas and examines the influence of various factors on these expenditures. The estimation is based on the latest data from the Statistical Center of Iran and uses first-order multiple regression analysis through the Ordinary Least Squares (OLS) method, implemented at the national level using SPSS and STATA software. The findings indicate that household characteristics such as age, gender, education level, marital status, income, total household expenditure, and level of economic facilities have a significant effect on religious expenditures in both urban and rural households. Although the share of these expenditures is higher in rural households than in urban ones, both have shown a declining trend over two five-year periods.