In mathematics integral has several meanings:
- In calculus, the integral of a function is the area below its graph. See integral.
- A real number is "integral" if it is an integer.
- The integral value of a real number x is defined as the largest integer which is less than, or equal to, x. The integral value of x is often denoted by and called the floor function.
- In abstract algebra, an integral domain is a commutative ring with 0 ≠ 1 in which the product of any two non-zero elements is always non-zero. Integral domains are generalizations of the integers.
- In number theory, an element of a number field is called integral if it is an algebraic integer.