Kaithahar Kalan is a village in Rajpur tehsil in district of Buxar, Bihar, India. As per the data provided by Census of India in 2011, total population of Kaithahar Kalan was 3,313 which includes 1,743 males and 1,570 females. Kaithahar Kalan covers 435 ha area. Pincode of Kaithahar Kalan is 802128.