The parts you upload for a multipart upload can be any size up to and including five gigabytes. However, the minimum size for the parts you include in a complete multipart upload request, except the last part, is one megabyte. The last part can be smaller than one megabyte.
A multipart upload can have at most ten thousand parts. Therefore, the maximum size for the object resulting from a multipart upload is five terabytes (ten thousand times five gigabytes).