Units Conversion Factors (SI and Metric)

History of Units Conversion Factors:

1. There are two types of unit systems used in the world. These are:
   1. Metric system.
   2. SI system

2. WHO recommends SI units (systeme international d’unities).

There are 7 SI base units, as follows:

SI unit	Symbol	Used for
Kilogram	Kg	Weight
Metre	m	Length
Seconds	s	Time
mole	mol	It is the amount of the substance
Kalvin	k	Temperature
Ampere	A	Electricity
Candela	cd	Luminous intensity

Metric and SI, units Conversion Factors, are:

To convert from	Into	Multiplication factor
Centimeter	Inches	0.39
Inches	Centimeter	2.54
Meter	Yards	1.09
Yards	Meter	0.91
Gallons	Liters	3.78
Liter	Gallons	0.26
Gallon	Liter	3.78
Gram	Ounce	0.035
Ounce	Gram	28.4
Kilogram	Pound	2.2
Pound	Kilogram	0.45
Centigrade ( C )	Fahrenheit (F)	F = (C x 1.8) + 32
Fahrenheit	Centigrade	C = ( F — 32 ) x 0.556
%weight/volume (weight=w and volume=v)	Molar solution (M)	M = %w/v x 10/gram mol. weight
%weight/volume	Normal solution (N)	N = % w/v x 10 /equivalent weight
mg/dL	meq/L	meq/L = mg/dL x 10 / equivalent weight

Symbols used with SI units:

Factor (value)	Prefix	The symbol in the SI system	Divided by
10-1	deci-	d  (10-1)	10
10-2	centi-	c  (10-2)	100
10-3	milli-	m (10-3)	1000
10-6	micro-	µ  (10-6)	1 000, 000
10-9	nano-	n  (10-9)	1 000, 000, 000
10-12	pico-	p  (10-12)	1 000,000,000,000
10-15	femto-	f  (10-15)	1 000, 000, 000,000, 000
10-18	atto-	a (10-18)	1 000, 000, 000, 000, 000, 000
			Multiply by
101	Deka	da  (101)	10
102	hecto-	h  (102)	100
103	Kilo-	k  (103)	1000
106	mega-	M  (106)	1000,000
109	giga-	G  (109)	1000, 000, 000
1012	tera-	T  (1012)	1 000, 000, 000, 000