Rational may refer to:
Rational number, a number that can be expressed as a ratio of two integers Rational point of an algebraic variety, a point defined over the rational numbers Rational function, a function that may be defined as the quotient of two polynomials Rational fraction, an expression built from the integers and some variables by addition, subtraction, multiplication and division Rational pricing an assumption in financial economics that asset prices will be arbitrage free Rational Software, a software company now owned by IBM Tenberry Software, formerly Rational Systems, a defunct American software company Rational AG, a German manufacturer of food processors RationaL, stage name of Canadian hip-hop artist Matt Brotzel The Rationals, a former American rock and roll band Rational, a personality classification in the Keirsey Temperament Sorter Priestly breastplate, called a 'rational' in older Biblical translations, from the Vulgate name for the breastplate: 'rationale'
See also Rationality Rationale (disambiguation) Rationalism (disambiguation) Rationalization (disambiguation)