Vector Magnitude Calculator to find the resulting magnitude of 2D and 3D vectors. The concept of the magnitude is used to describe the length of physical quantities which have both a magnitude and a direction associated with them. The magnitude or length of a 2D or 3D vector is denoted by |A|. It is a scalar and must be non-negative. Any vector whose length 1 is called a unit vector; unit vectors will usually be denoted by e. The magnitude of a vector can be calculated by taking the square root of the sum of the squares of its components. When it comes to calculate magnitude of 2D or 3D vectors, this vector magnitude calculator is an essential tool to make your calculation simple.