In order to estimate flammability in forest and wild land areas of USA, Keetch and Byram (1968) developed a drought index namely Keetch-Byram drought index (KBDI). Conceptually, using daily precipitation and daily maximum temperature, KBDI has the potential to describe moisture deficiency in upper soil layer (Keetch and Byram 1968). KBDI that use minimum number of meteorological parameters (precipitation, maximum temperature), was originally developed for the southeastern forest of the United States and has been extensively used for re potential assessment in the U.S. (Keetch and Byram 1968). This index, which conceptually describes the soil moisture (Dolling et al. 2005) with several simple criteria, is based on the amount of daily precipitation, daily maximum temperature and mean annual precipitation. The output varies from 0 to 800, where 0 represents the soil saturation and 800 indicates the most severe drought. Generally, the output is categorized into four classes with 200 intervals. Each class represents a particular concept. More detailed explanation for the calculations of this index can be found in Keetch and Byram (1968) and Janis et al. (2002). We've developed the KBDIS (Keetch-Byram Drought Index Software) for calculating Keetch-Byram Index as a drought index. You can import your data as excel file and calculate KBDI in yearly, seasonally, monthly, and daily Formats. This software can draw linear, Columnar, and box-plot graphs. The user can easily determine the field capacity option in this tool.