Linear Algebra & Matrices

Scalar Triple Product Calculator

Calculate a · (b × c) and its signed volume exactly.

Linear Algebra & Matrices

Enter vector components

Exact rational arithmetic
  1. 1EnterProvide the known values
  2. 2CalculateResults update automatically
  3. 3VerifyReview the details and units
Try an example
Vector a

3 components

Vector c

3 components

Use ordinary signed decimals. Fractions, commas, and scientific notation are not accepted in this first batch.

Exact result

Enter valid values to see the result.

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Understand the subject

What does a scalar triple product measure?

The scalar triple product turns three three-dimensional vectors into one signed volume. Its absolute value is their parallelepiped’s volume.

Use it to test coplanarity and calculate oriented three-dimensional volume.

The relationship

The defining relationship

See the structure

What the calculation is doing

Worked interpretation

Read the result in context

u·(v×w)

Interpret with care

Important boundary

Changing the order can change the sign; a zero result means the vectors are coplanar or dependent.

Use the Matrix Calculator to experiment with small exact matrix operations before applying a more specialized route.

Quick guide

How to use this calculator

  1. Enter three three-dimensional vectors.
  2. Preserve the requested vector order.
  3. Read the signed scalar and its non-negative volume magnitude.

Calculation method

Cross two vectors, then take a dot product

The scalar triple product a · (b × c) is the signed volume of the parallelepiped formed by the ordered vectors. Its absolute value is the geometric volume.

Worked example

Standard basis volume

Use the three standard basis vectors in cyclic order.

⟨1,0,0⟩ · (⟨0,1,0⟩ × ⟨0,0,1⟩) = 1

Supported inputs

Precision and limits

Vector size

General vectors may contain 2–8 components; three-dimensional products require exactly three.

Entry precision

Each signed decimal may contain up to 30 digits and 15 decimal places.

Square roots

Squared magnitudes remain exact. Irrational roots and normalized components are explicitly labelled approximations.