Linear Algebra Basic

Dot Product Calculator

Enter two vectors — get the dot product with full step-by-step breakdown, angle between vectors, and geometric interpretation.

Vector Inputs
Dimensions:
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Result
Result will appear here after you click Compute.
Vector Visualization
Step-by-Step Solution
Step 01
What is the dot product?
Step 02
Multiply corresponding components
Step 03
Sum all the products
Step 04
The result
Step 05
What does it mean?
The Dot Product Formula
A · B = a₁b₁ + a₂b₂ + ⋯ + aₙbₙ = |A||B| cos θ

For two vectors A = (a₁, a₂, …, aₙ) and B = (b₁, b₂, …, bₙ), the dot product sums the products of corresponding components.

The geometric form |A||B| cos θ reveals the angle between vectors. When A · B = 0, the vectors are orthogonal (perpendicular). Positive means roughly same direction; negative means opposing.

The dot product is the backbone of projections, correlation, and neural networks. Mastering it unlocks matrix multiplication (which is just rows dot-producted with columns).
When To Use Dot Products
  • Finding the angle between two vectors
  • Testing orthogonality (perpendicularity)
  • Computing vector projections
  • Understanding matrix multiplication row-by-row
  • Cosine similarity in machine learning

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