Abstract An empirical mathematical model due to Heuklon was used to evaluate atmospheric content of ozone over Association of South East Asian Nations (ASEAN) countries. The model is dependent on latitude, longitude, and day of the year. A comparison of the computed data of ozone was made with the measured data. The measured data on ozone content was collected from the meteorological departments of the ASEAN countries. Our preliminary calculations indicate that the model can estimate the ozone content in the northern as well as the southern hemisphere with a maximum error of 10%.