Confidence Interval (z-based)
Calculate Confidence Interval (z-based) instantly with the exact formula and a worked example. Free online calculator — no signup, works on mobile.
Confidence Interval (z-based)
x̄
σ
n
95% half-width
5.3677
More about: Confidence Interval (z-based)
What it calculates
The “Confidence Interval (z-based)” calculator computes 95% half-width from 3 parameters: x̄, σ, n.
A core calculation for studying, engineering tasks, and checking solutions.
Example calculation
With parameters x̄ = 100, σ = 15, n = 30 the result is 5.37.
How to use
- Enter the parameter values — every field above is adjustable with a slider.
- The result and related metrics are calculated automatically as you type.
- Use the additional metrics shown (if any) where needed.
- Copy the result or bookmark the page.