fraction

fraction (0–1)

Concentrationexact by definition

The fraction is the plain dimensionless ratio, running from 0 to 1, where percent runs from 0 to 100. One fraction is exactly 100 percent, and the factor of 100 is exact by definition. It is the form that belongs inside equations, since a formula expecting a fraction will silently give an answer a hundred times too large if fed a percentage.

Watch out: Efficiency, relative humidity and blowdown ratios are all quoted as percentages in conversation and used as fractions in arithmetic. Mixing the two is the most common dimensionless-unit error there is, and it is invisible in the units because both are dimensionless.

1 fraction 100 %