Vector Magnitude Calculator

Find the Euclidean length or norm of any 2D or 3D vector from its components.

Calculate vector magnitude
Enter the vector components below. Use zero for z when calculating a 2D vector.

About vector magnitude

Vector magnitude is the length of a vector, independent of the direction in which it points. It is also called the Euclidean norm or simply the norm. For a vector with components x, y, and z, magnitude is the square root of x squared plus y squared plus z squared. The formula is an extension of the Pythagorean theorem from a right triangle into three-dimensional coordinate space. For a two-dimensional vector, set z to zero. A familiar example is the vector (3, 4), whose magnitude is 5 because 3 squared plus 4 squared equals 25. In three dimensions, the same logic first combines perpendicular distances in the xy-plane and then incorporates depth along the z-axis. The vector (2, 3, 6), for example, has magnitude 7 because its squared components sum to 49. Magnitude is always nonnegative. Changing every component's sign reverses the vector's direction but leaves its length unchanged, because squaring removes the signs. The zero vector is the only vector with magnitude zero. Decimal, fractional, and negative components are all valid inputs, provided every coordinate uses the same unit and coordinate scale. This measurement appears throughout mathematics, physics, engineering, data science, and computer graphics. A velocity vector's magnitude is speed. A force vector's magnitude is the force strength. A displacement vector's magnitude is straight-line distance between its start and end points. In machine learning and numerical analysis, norms measure the size of parameter vectors, errors, and distances between observations. Magnitude is also used to normalize a vector. Dividing each component of a nonzero vector by its magnitude produces a unit vector that points in the same direction but has length one. Unit vectors make it easier to separate direction from scale. Magnitudes also appear in dot-product angle formulas and in tests of orthogonality and convergence. The calculator uses the built-in hypotenuse operation for stable floating-point evaluation and displays up to six decimal places. Exact square-root forms may be preferable in symbolic algebra, while the decimal result is convenient for measurement and applied work. Use zero for a missing dimension rather than leaving the field blank so the calculator can distinguish a complete 2D vector from incomplete input.

Vector magnitude examples

VectorMagnitudeExplanation
(3, 4)5The square root of 9 + 16 is 5.
(2, 3, 6)7The squared components sum to 49.
(-1, -2, -2)3Negative signs disappear when components are squared.

How to calculate vector magnitude

  1. Enter the x and y components of the vector.
  2. Enter the z-component, or enter zero for a two-dimensional vector.
  3. Select Calculate magnitude to evaluate the Euclidean norm.
  4. Read the result and use Reset to calculate another vector.

Vector magnitude FAQ

What is the magnitude of a vector?

Magnitude is the vector's nonnegative length. It measures size without including any information about direction.

How is vector magnitude calculated?

Square every component, add those squares, and take the square root. This is the Pythagorean theorem applied to coordinate components.

Can a vector magnitude be negative?

No, a length cannot be negative. Only the zero vector has magnitude zero, while every nonzero vector has positive magnitude.

How do I calculate a 2D vector?

Enter the x and y values normally and enter zero for z. The three-dimensional formula then reduces to the standard two-dimensional formula.

What is the difference between magnitude and direction?

Magnitude tells you how long or strong a vector is. Direction tells you where it points, often expressed with angles or a unit vector.