The International Electrotechnical Commission (IEC) uses binary (base-2), meaning steps of 1,024 (2102^{10}) – KiB, MiB, GiB, etc. Meanwhile, the International System of Units (SI) uses decimal (base-10), meaning steps of 1,000 (10310^3) – KB, MB, GB, etc.

IEC Unit Formula Exact Bytes SI Unit Formula Exact Bytes Difference
KiB (Kibibyte) 2102^{10} 1,024 kB (Kilobyte) 10310^3 1,000 2.40%
MiB (Mebibyte) 2202^{20} 1,048,576 MB (Megabyte) 10610^6 1,000,000 4.86%
GiB (Gibibyte) 2302^{30} 1,073,741,824 GB (Gigabyte) 10910^9 1,000,000,000 7.37%
TiB (Tebibyte) 2402^{40} 1,099,511,627,776 TB (Terabyte) 101210^{12} 1,000,000,000,000 9.95%
PiB (Pebibyte) 2502^{50} 1,125,899,906,842,624 PB (Petabyte) 101510^{15} 1,000,000,000,000,000 12.59%
EiB (Exbibyte) 2602^{60} 1,152,921,504,606,846,976 EB (Exabyte) 101810^{18} 1,000,000,000,000,000,000 15.29%
ZiB (Zebibyte) 2702^{70} 1,180,591,620,717,411,303,424 ZB (Zettabyte) 102110^{21} 1000 Hexillion 18.06%
YiB (Yobibyte) 2802^{80} 1,208,925,819,614,629,174,706,176 YB (Yottabyte) 102410^{24} 1 Septillion 20.89%
RiB (Ronnibyte) 2902^{90} 1,237,940,039,285,380,274,899,124,224 RB (Ronnabyte) 102710^{27} 1 Octillion 23.79%
QiB (Quebibyte) 21002^{100} 1,267,650,600,228,229,401,496,703,205,376 QB (Quettabyte) 103010^{30} 1 Nonillion 26.77%