Cross Product Calculator
a × b in 3D with the determinant expansion shown, the magnitude |a||b|sin θ, the parallelogram and triangle areas, the unit normal and the right-hand rule.
Related tools
All Matrices & vectors tools →Open Cross Product Calculator and you get an answer straight away, with no account to create. Its place is under Matrices & vectors; Dot Product Calculator and Tensor Product Calculator (Kronecker product A ⊗ B) answer the questions closest to this one.
How to use it
- Open the tool — no signup or install needed.
- Enter your input or adjust the available options.
- Get your result instantly, then copy or download it.
Frequently asked questions
What does Cross Product Calculator do?
a × b in 3D with the determinant expansion shown, the magnitude |a||b|sin θ, the parallelogram and triangle areas, the unit normal and the right-hand rule.
When would I actually use this?
Checking a decomposition done by hand, solving a linear system, and finding the eigenvalues that describe how a transformation stretches space.
What is the most common mistake?
Inverting a matrix to solve a system. Elimination or a factorisation is both faster and far more stable numerically; an explicit inverse amplifies rounding error, especially when the matrix is close to singular.
How is Cross Product Calculator different from Dot Product Calculator?
They sit next to each other but answer different questions: Dot Product Calculator is the one to open when you need it to a·b in 2 to 10 dimensions with the term-by-term sum, both magnitudes as exact radicals, the angle in degrees and radians, the projections, and a figure. Parallel and orthogonal are decided in exact fractions, so (1,1,1)·(2,2,2) returns 0°, not NaN. Pick whichever matches what you're starting from — both are free.
Is there a tool for the next step?
Tensor Product Calculator (Kronecker product A ⊗ B) is the closest one after this: The Kronecker product of two matrices of any shape, block by block, in exact fractions or 6 / 10 significant digits — with the (m·p) × (n·q) size rule and the identities on rank, transpose and determinant.
What else is worth having open alongside it?
Product notation calculator (pi notation) and Angle Between Two Vectors Calculator — they come up in the same task often enough to be worth a second tab.
Where do the figures come from?
The decompositions follow their textbook definitions with partial pivoting where it applies. Results are exact for small integer matrices and subject to floating-point rounding otherwise.