QiLing Tools

🪜RREF Calculator with Steps - Row Reduction, Det & Inverse

When you learn linear algebra the working matters more than the answer. Enter a matrix up to 6 × 6 and the calculator row-reduces it one elementary row operation at a time, writing each step in textbook form — R2 ← R2 − 3R1, R1 ↔ R2, R1 ← R1 ÷ 2 — followed by the matrix after that step, with the pivot and the changed rows highlighted. It reduces to row echelon form (Gaussian elimination) or reduced row echelon form (Gauss-Jordan), computes the determinant both by elimination and by cofactor (Laplace) expansion, finds the inverse by reducing [A | I], gives the rank and pivot columns, and solves Ax = b from the augmented matrix, reporting a unique solution, no solution or the general solution with free variables. Everything uses exact fractions, so 1/3 never turns into 0.3333.

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How to use Matrix Step-by-Step

  1. 1Choose the operation: RREF, row echelon form, determinant, inverse, rank or solve Ax = b
  2. 2Set the size and fill in the matrix (integers, fractions like 3/4 or decimals; you can paste a block from a spreadsheet)
  3. 3Follow each row operation and the resulting matrix down to the final answer

FAQ

What is the difference between REF and RREF?
In row echelon form (REF) each leading entry (pivot) is to the right of the one above and everything below a pivot is zero — the result of Gaussian elimination. Reduced row echelon form (RREF) additionally makes every pivot 1 and clears the rest of each pivot column — the result of Gauss-Jordan elimination. A matrix has exactly one RREF but many possible REFs.
How do row operations change the determinant?
Swapping two rows flips its sign, adding a multiple of one row to another leaves it unchanged, and multiplying a row by k multiplies it by k. The calculator uses only swaps and row additions to reach an upper-triangular matrix, so det(A) = (product of the diagonal) × (−1)^(number of swaps), and it checks the answer with cofactor expansion.
How do you find an inverse with row operations?
Write A next to the identity matrix as [A | I] and row-reduce the whole thing until the left half becomes I; the right half is then A⁻¹. If a row of zeros appears on the left, det(A) = 0 and A has no inverse.
How can I tell whether a linear system has a solution?
Reduce the augmented matrix [A | b] and compare ranks. If rank(A) < rank([A | b]) a row reads 0 = non-zero and there is no solution. If the ranks are equal and match the number of unknowns the solution is unique; if they are equal but smaller, there are infinitely many solutions and the variables without pivots are free parameters.