Rate Unit

When applying a rate, there must be a relationship between the unit used for measurement and the unit used for rating.

For instance, load balancers is measured in hours (or partial hours) in AWS. Data transfer is measured in GB per month in AWS. There is a charge associated to million I/O requests. Etc.

For that reason, it is necessary to understand the rate unit used. Rates need to be defined with the unit that is applied and checked when using the rate.

For instance, a rate for data transfer needs to be defined in B (MB, GB, TB, PB, etc). When trying to apply a rate to an input, a conversion needs to be done.

Example: Input in MB, rate in GB. A conversion of MB to GB is done before applying the rate dividing the input by 1,000. Input in GB, rate in GiB. A conversion of GB to GiB is done before applying the rate multiplying the number by 1,000/1,024. Input in GB, rate in Mbps. There is no conversion, so the conversion is 0. This is normally a mistake when setting up rates.

The International System of Units consists of a set of base units, a set of coherent derived units, and a set of decimal-based multipliers that are used as prefixes.

Standard prefixes for the SI units of measure

Multiples

Prefix name	deca	hecto	kilo	mega	giga	tera	peta	exa	zetta	yotta
Prefix symbol		da	h	k	M	G	T	P	E	Z
Factor	100	101	102	103	106	109	1012	1015	1018	1021

Submultiples

Prefix name		deci	centi	milli	micro	nano	pico	femto	atto	zepto	yocto
Prefix symbol		d	c	m	μ	n	p	f	a	z	y
Factor	100	10−1	10−2	10−3	10−6	10−9	10−12	10−15	10−18	10−21	10−24

Specific units of IEC 60027-2 A.2 and ISO/IEC 80000 IEC prefix

Representations Customary prefix

Name	Symbol	Base 2	Base 1024	Value	Base 10	Name	Symbol
kibi	Ki	2 10	1024 1	1024	= 1.024×103	kilo	k or K
mebi	Mi	2 20	1024 2	1048576	≈ 1.049×106	mega	M
gibi	Gi	2 30	1024 3	1073741824	≈ 1.074×109	giga	G
tebi	Ti	2 40	1024 4	1099511627776	≈ 1.100×1012	tera	T
pebi	Pi	2 50	1024 5	1125899906842624	≈ 1.126×1015	peta	P
exbi	Ei	2 60	1024 6	1152921504606846976	≈ 1.153×1018	exa	E
zebi	Zi	2 70	1024 7	1180591620717411303424	≈ 1.181×1021	zetta	Z
yobi	Yi	2 80	1024 8	1208925819614629174706176	≈ 1.209×1024	yotta	Y

You can also use time with international prefixes using the second (s) as a base, or use Minute, Hour, Day, Week, Month, Year, Decade, etc.