What this calculator does
Vector dot product works out scalar dot product of two 3D vectors, and the angle between them. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulaa·b = a₁b₁ + a₂b₂ + a₃b₃ = |a||b|cos θ
The inputs explained
| Field | What to enter |
|---|---|
| a₁ (x) | A number. Starts at 2. |
| a₂ (y) | A number. Starts at 3. |
| a₃ (z) | A number. Starts at -1. |
| b₁ (x) | A number. Starts at 1. |
| b₂ (y) | A number. Starts at 0. |
| b₃ (z) | A number. Starts at 4. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with a₁ (x)
Every other input is held at the calculator’s starting values while a₁ (x) varies. Select any row to load that scenario into the calculator.