A method of measuring durability of a nonvolatile memory device that includes a plurality of memory blocks, the method including: periodically receiving a read command for a first memory block among the plurality of memory blocks; periodically performing a read operation on the first memory block based on the read command; periodically outputting at least one cell count value associated with the first memory block based on a result of the read operation; and periodically storing durability information associated with the first memory block in response to a periodic reception of the durability information, the durability information being obtained by accumulating the at least one cell count value.