How to use this calculator

A z-score tells how many standard deviations a value lies above or below a mean.

The method

z = (x − μ)/σ

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

WORKED EXAMPLE INPUT

Value x: 85, Mean μ: 70, Standard deviation σ: 10

Select Calculate to evaluate these example values.

Scope and limitations

Standard deviation must be positive.

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.