Dimension Calculator Linear Algebra Guide
What Dimension Means
A dimension calculator helps you study a matrix as a map. The rows and columns show how vectors move. The most useful number is rank. Rank counts the pivot columns after reduction. It also gives the dimension of the column space. The same value gives the dimension of the row space. These two spaces can look different. Yet their dimensions are always equal.
Rank and Nullity
Nullity is another key result. It counts free variables in a homogeneous system. A large nullity means many input vectors go to zero. A zero nullity means the columns are independent. For a matrix with n columns, rank plus nullity equals n. This is the rank nullity theorem.
Reduced Form
The calculator reduces your matrix to row reduced echelon form. This form makes pivots easy to see. Pivot columns form a basis pattern for the column space. Nonzero rows form a basis pattern for the row space. Free columns describe the solution space. The tool also reports left nullity. This value is m minus rank for an m by n matrix.
Subspace Comparison
You can also compare two subspaces. Enter bases as columns in the first and second matrices. The tool finds the dimension of each span. It then joins the columns. The rank of the joined matrix gives the dimension of the sum. The intersection dimension follows from the formula dim U plus dim V minus dim U plus V.
Study Uses
Use this page for homework checks, lecture review, and quick planning. It supports decimals, fractions written as decimals, negative values, and rectangular matrices. Results are rounded for display only. The calculations use a small tolerance to avoid floating noise. Always check exact symbolic work when your course needs proof.
Why It Helps
Dimension answers explain structure. They do more than solve one system. They show independence, dependence, constraints, and freedom. A matrix with full column rank has independent columns. A matrix with full row rank reaches the whole output space. These facts help with transformations, least squares, data models, and many applied problems.
For best results, keep each row the same length. Put missing entries as zero. Review pivot positions before using exported files. This habit makes errors easier to catch and explain during exams and regular practice.