What does factor mean?
A factor is any circumstance, condition, or element that contributes to producing a result. When analysts say that price was a key factor in consumer behaviour, they are identifying price as one of several influences shaping an outcome. Beyond this general use, factor carries important technical meanings: in mathematics, a factor is a number that divides into another exactly, or one of two or more quantities multiplied together to give a product; in medicine and biology, factors such as growth factors or clotting factors are substances that play specific roles in bodily processes; and in commerce, historically, a factor was an agent who sold goods on behalf of a merchant, a sense still preserved in terms like 'factor's commission'. The word derives from Latin factor, meaning 'one who does or makes', from facere, 'to do'. It functions primarily as a noun but also serves as a verb, meaning to include something as a consideration — as in factoring costs into a budget.
A circumstance, fact, or influence that contributes to a result.
"Motivation is often the deciding factor between success and failure."
(Mathematics) A whole number that divides exactly into another number without leaving a remainder, or one of two or more quantities multiplied together to form a product.
"Seven is a factor of forty-two."
(Commerce, historical) An agent entrusted to sell goods on behalf of a merchant or manufacturer.
"The merchant sent his cotton to a factor in Liverpool for sale."
This sense is now largely historical but survives in some commercial and legal terminology.
To include something as a consideration when making a calculation or decision (usually followed by 'in' or 'into').
"Remember to factor in the cost of shipping before placing your order."
Standard plural used across all noun senses.
"Several environmental factors contributed to the decline of the species."
The word 'factor' comes from the Latin for 'maker' — so every time you say 'the deciding factor,' you're literally naming the thing that makes the outcome happen.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of factor
Factor comes directly from Latin factor, meaning 'one who does or makes', formed from the past participle stem of facere, 'to do' or 'to make'. It entered English in the late Middle Ages, initially referring to a commercial agent who acted on behalf of merchants. Over time the word broadened to mean any agent or element that produces an effect, and by the seventeenth century it had acquired its mathematical sense of a quantity multiplied by another. Cognates sharing the same Latin root include manufacture, benefactor, faction, and factitious.
Related word forms
How factor is actually used
The word is neutral in tone and common in both formal and informal registers. It appears frequently in analytical, scientific, and business writing. The verb form ('to factor something in') means to include something as a consideration when making a decision.
Easily confused with factor
"Fractor" is not a standard English word, but it occasionally appears as a coined term in mathematics or engineering contexts; "factor" refers to a contributing element or divisor.