How many megabytes = 1 Gigabyte - Gigabyte Computers & Internet

1024 MB = 1 GB
This is due to binary (2*2*2...) multiplication.

In most other everyday measurements, it is calculated as power of tens.
List from Greek words, used for multipliers:
femto = f = unit / 10^18?
atto = a = unit / 10^15?
pico = p = unit / 10^12
nano = n = unit / 10^9
micro = u = unit / 10^6
milli = m = unit / 10^3
centi = c = unit / 10^2
deci = d = unit / 10^1
Deca = unit * 10^1
Hecta = unit * 10^2
Kilo = K = unit * 10^3
Mega = M = unit * 10^6
Giga = G = unit * 10^9
Tera = T = unit * 10^12
Peta = P = unit * 10^15?
Exa = E = unit * 10^18?
Note: extreme values femto, atto, Peta and Exa seldom used except in laboratories. Can't remember order of these marked '?'.
Will look it up and edit if necessary.
Other used in electronics, electrical, weight, measurement, distance, speed, temperature, etc.
The symbol is always the prefix, followed by unit.
Case of letters is important.
ml for milliliter, but MHz for Megahertz.
Km, Dg, dB, Tb/sec, EV...