An accelerator, a method of operating the accelerator, and an electronic device including the accelerator. A method of operating the accelerator configured to perform a target operation includes packing input data with a data layout determined based on a word width of a memory in the accelerator and a spatial size of a filter to be applied to the target operation and storing the packed input data in the memory, and performing the target operation between a portion of the input data stored in a same word in the memory and weights of the filter.