Zettabyte（ZB,泽它字节或皆字节）是一种资讯计量单位，现今通常在标示网络硬盘总容量，或具有大容量的储存媒介之储存容量时使用。
1ZB = 1,000EB
1ZB = 1,000,000 (10)PB
1ZB = 1,000,000,000 (10)TB
1ZB = 1,000,000,000,000 (10)GB
1ZB = 1,000,000,000,000,000 (10)MB
1ZB = 1,000,000,000,000,000,000 (10)KB
1ZB = 1,000,000,000,000,000,000,000 (10)B
另外，Zettabyte往往亦可以指Zebibyte，其换算公式是：
1ZiB = 1,024 EiB
1ZiB = 1,048,576 (1024)PiB
1ZiB = 1,073,741,824 (1024)TiB
1ZiB = 1,099,511,627,776 (1024)GiB
1ZiB = 1,125,899,906,842,624 (1024)MiB
1ZiB = 1,152,921,504,606,846,976 (1024)KiB
1ZiB = 1,180,591,620,717,411,303,424 (1024)B