It is suggested that there are about 86 million t (at Kivioli 12.5, Kohtla-Jarve 70.7 and Narva 3.0 million t) oil-shale semi-coke and coke deposited in the Estonian landfills since 1921. However, there is no explanation how these volumes were calculated and no data about the volumes of semi-coke formed at Vanamoisa, Kohtla-Nomme and Sillamae. According to the calculations based on operation of processing units, 74.7% of dry spent oil shale deposited in Estonia is located at Kohtla-Jarve. These deposits (83.22 million t) consist of semi-coke and coke, 48.75 and 34.47, respectively. At Kivioli mostly semi-coke is deposited - 19.2 million t (17.2%). Ash-like spent shale is deposited at Narva (4.34 million t, 3.9%), the landfills of other locations at Vanamoisa, Kohtla-Nomme and Sillamae hold 2.77, 1.09 and 0. 7 million t of SC (2.5, 1.0 and 0.7%), respectively. This paper presents a method for calculation the volume of spent shale.