The absolute value of a complex number z=a+bi, also called the modulus, is the distance from the origin to the point (a,b) in the complex plane.

The number z can be interpreted as a vector and therefore, its length can be calculated using the Distance Formula.

For example, the absolute value of 3-4i is |3-4i| = sqrt(3^2 + (-4)^2) = 5.