Conversion factor

Conversion of units refers to conversion factors between different units of measurement for the same quantity.
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Noun
1. factor by which a quantity that is expressed in one set of units must be multiplied in order to convert it into another set of units
(hypernym) factor

A figure published by the CBOT used to adjust a T-Bond hedge for the difference in maturity between the T-Bond contract specifications and the T-Bonds being hedged.

(See also British Thermal Unit) A number that translates units of one system into corresponding values of another system. Conversion factors can be used to translate physical units of measure for various fuels into British Thermal Unit (BTU) equivalents. (DOE3) (DOE4)

 Say it 
A conversion factor is a fraction that relates one unit to another. Multiplying a measurement by a conversion factor changes the units of the measurement. For example, since 1 in = 2.54 cm, to convert 10 inches to centimeters,
(10 in)= 25.4 cm

2.54 cm
1 in