How to use this calculator

The perimeter is the total length around the triangle.

The method

Perimeter = a + b + c

Enter your values in the labeled fields and choose Calculate. The result panel shows the answer and supporting values when useful.

WORKED EXAMPLE INPUT

Side a: 5, Side b: 6, Side c: 7

Select Calculate to evaluate these example values.

Scope and limitations

The calculator checks the triangle inequality so impossible side combinations are rejected.

Common questions

Can I use different units?

Use consistent units unless this page is a unit converter. The result follows the units implied by the inputs.

Are results exact?

Displayed values may be rounded. Keep extra precision for important follow-up calculations.

Methods & verification

Formulas use standard mathematical definitions and fixed unit factors where applicable. See our methodology for numerical conventions, rounding, privacy, and limitations.