How to use this calculator

Percentage difference is useful when neither value is a designated baseline.

The method

Percentage difference = |a − b| / ((|a| + |b|)/2) × 100

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

WORKED EXAMPLE INPUT

First value: 80, Second value: 100

Select Calculate to evaluate these example values.

Scope and limitations

Both values cannot be zero at the same time. Uses real-number arithmetic and rounds display values without changing the entered inputs. Check important results independently.

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.