A nonvolatile memory device includes a memory cell array, an input current generator, an operation cell array and an analog-to-digital converter. The memory cell array includes NAND strings storing multiplicand data, wherein first ends of the NAND strings are connected to bitlines and second ends of the NAND strings output multiplication bits corresponding to bitwise multiplication of the multiplicand data stored in the NAND strings and multiplier data loaded on the bitlines. The input current generator generates input currents. The operation cell array includes switching transistors. Gate electrodes of the switching transistors are connected to the second ends of the NAND strings. The switching transistors selectively sum the input currents based on the multiplication bits to output the output currents. The analog-to-digital converter converts the output currents to digital values.