Confidence Interval Calculator
Estimate the range where the true population mean likely falls.
- Free Online Tool
- Instant Results
- Mobile Friendly
- No Installation
- Secure & Private
Result
Understanding This Calculator
Confidence Interval Formula
Range estimate for a population parameter.
CI = x̄ ± (z × σ / √n)
- x̄: Sample Mean
- z: Z-score (1.96 for 95%)
- σ: Standard Deviation
- n: Sample Size
Example 1
Mean=50, σ=10, n=25, 95% Conf (z=1.96)
- Error = 1.96 × (10 / 5) = 1.96 × 2 = 3.92
- CI = 50 ± 3.92 -> [46.08, 53.92]
How to Use
- Enter sample mean.
- Enter standard deviation.
- Enter sample size.
- Select confidence level.
Frequently Asked Questions
How do I use the Confidence Interval Calculator?
Enter your values in the input fields, and the result will appear instantly.
Is this calculator free to use?
Yes, this calculator is 100% free and does not require any registration or subscription.
Is it mobile-friendly?
Absolutely! Our tool is optimized for all devices, including mobile phones, tablets, and desktop computers.