Rational (disambiguation)

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 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'