This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized grain-size data of sediment core PG2133, retrieved in 2013 from Lake Bolshoe Toko (Yakutia, Russia) at 26 m water depth. The glacial lake Bolshoe Toko is in the deciduous forest mountain area. It lies at an elevation of ca. 919 m a.s.l. with a surface area of ca. 83.243 km2 and a maximum lake water depth of estimated 72.5 m. The 3.75 m sediment core was retrieved by a UWITEC piston corer during the RU-Land_2013_Yakutia expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). Grain-size was measured by laser diffractometry using a Malvern Mastersizer 3000 at AWI Potsdam.