Parallelepiped Volume Calculator
Calculate the volume and surface area of a parallelepiped from three vectors, four vertices, or edge lengths and angles with step-by-step formulas.
What Is a Parallelepiped?
A parallelepiped is a three-dimensional shape with six parallelogram faces. When all angles are right angles, it becomes a rectangular prism. In vector geometry, three adjacent edge vectors that share a common starting point fully describe the shape.
Volume Formula Using Vectors
The volume equals the absolute value of the scalar triple product:
$$V = \left|(\vec{a} \times \vec{b}) \cdot \vec{c}\right|$$Here \(\vec{a}\), \(\vec{b}\), and \(\vec{c}\) are three non-coplanar edge vectors. The cross product \(\vec{a} \times \vec{b}\) gives a vector perpendicular to both inputs, and the dot product with \(\vec{c}\) measures how far the shape extends along that direction.
Surface Area Formula
The total surface area combines the areas of all three unique parallelogram faces, counted twice:
$$A = 2\left(|\vec{a} \times \vec{b}| + |\vec{b} \times \vec{c}| + |\vec{a} \times \vec{c}|\right)$$Example With Three Vectors
Let \(\vec{a} = [1, 2, 3]\), \(\vec{b} = [5, -4, 7]\), and \(\vec{c} = [-5, 1, 12]\).
- Compute \(\vec{a} \times \vec{b} = [34, -4, -26]\)
- Compute \((\vec{a} \times \vec{b}) \cdot \vec{c} = -290\)
- Volume: \(V = |-290| = 290\)
Related tools: Vector Calculator, Matrix Determinant Calculator, and Volume Calculator.
Frequently Asked Questions
What does a zero volume mean?
If the scalar triple product is zero, the three vectors are coplanar and do not form a three-dimensional parallelepiped.
Can I use four vertices instead of vectors?
Yes. With vertices p, q, r, and s, build vectors a = q - p, b = r - p, and c = s - p, then apply the same volume formula.
How is volume calculated from edge lengths?
Use side lengths a, b, c and the angles between them. The volume includes a square-root correction term based on cosines of those angles.
Is a cube a parallelepiped?
Yes. A cube is a special parallelepiped where all edges are equal and all angles are 90 degrees.