- Factor used by cosmologists to represent the change of large distances with time: symbol R
- A number which is added, multiplied, or otherwise factored in to a measurement or reading, so as to provide the final displayed magnitude or value. Used, for instance, to convert a quantity into a value that is in the units displayed by a given scale.
- A number which divides or multiplies a measurement or reading, so as to change its scale of magnitude. Such a factor is usually an exponent the base of the number system utilized is raised to.