One thousand bytes. Actually 1024 bytes because computer storage is measured using base 2 (binary) number system with each digits value based on a power of 2 (1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1,024) rather than base 10 based on powers of 10 (1, 10, 100, 1,000) which is our everyday number system.