Kalkata yana zaune a cikin ƙananan Ganges Delta na gabashin Indiya kimanin 75 km (47 mi) yamma da iyakar kasa da kasa tare da Bangladesh; tsawo na birni shine 1.59 m (530 ft). Yawancin birnin ya kasance wuri ne mai banƙyama wanda aka sake dawowa a cikin shekarun da suka gabata don saukar da yawan jama'a. Sauran wuraren da ba a ci gaba ba, da aka sani da Gabashin Kolkata Wetlands, an sanya su a matsayin "ƙasa mai mahimmanci na duniya" ta Yarjejeniyar Ramsar (1975). Kamar yadda mafi yawan Indo-Gangetic Plain, ƙasa da ruwa suna da asali na asali.
yankin girgizar ƙasa III