2^2 bits=1 nibble
2^3 bits=1 byte
1KB(kilobyte)=2^10 bytes
1MB(megabyte)=2^20 bytes
1GB(gigabyte)=2^30 bytes
1TB(terabyte)=2^40 bytes
1PB(petabyte)=2^50 bytes
1EB(exabyte)=2^60 bytes
1ZB(zettabyte)=2^70 bytes
1YB(yottabyte)=2^80 bytes
EDIT: @Alexis: Yeah
Windows goes by 1000 doesnt it... Like right click/properties on hard Drive?
manufacturers use 1000, but the computer can only use 1024 so it seems like you have a bigger hard drive but in fact you don't.
Example:
My USB-stick has a memory of 512 MB according to the manufacturer but when I look on pc, it only has something of a 496MB