Search or browse the full table of SI prefixes and read off the symbol, power of ten, decimal factor and example for each. Use the converter below it to move a value between any two prefixes.
Twenty-four, running from quetta at ten to the thirtieth down to quecto at ten to the minus thirtieth. Ronna, quetta, ronto and quecto were added by the General Conference on Weights and Measures in 2022, mainly to cope with data storage and particle-scale measurements.
Every prefix from mega upward uses a capital symbol — M, G, T, P, E, Z, Y, R, Q — while kilo and below use lowercase, apart from the special case that kilo is a lowercase k. Getting this wrong matters: mK and MK differ by nine orders of magnitude.
No. The binary prefixes kibi, mebi and gibi mean 1024, 1024² and 1024³, while the SI kilo, mega and giga always mean powers of a thousand. That is why a 1 TB drive shows as about 931 GiB in an operating system.