Confidence Interval Calculator
About This Tool
Our confidence interval calculator helps you determine the range within which a population parameter (such as the mean or proportion) is likely to fall. Confidence intervals are a key concept in statistics, providing a measure of the uncertainty associated with your sample data.
Enter your sample statistics and select your desired confidence level to calculate the interval.
What is a Confidence Interval?
A confidence interval is a range of values, derived from sample statistics, that is likely to contain the value of an unknown population parameter. The confidence level (e.g., 95%) represents the proportion of intervals that would contain the true parameter if you were to take many samples.
For example, a 95% confidence interval means that if we were to take 100 different samples and compute a 95% confidence interval for each sample, then approximately 95 of the 100 confidence intervals will contain the true population parameter.
Formulas Used
Confidence Interval for Mean:
CI = x̄ ± (Z or t) * (σ/√n)
Where x̄ is the sample mean, Z or t is the critical value, σ is the standard deviation, and n is the sample size.
Confidence Interval for Proportion:
CI = p̂ ± Z * √(p̂(1-p̂)/n)
Where p̂ is the sample proportion, Z is the critical value, and n is the sample size.
Related Tools
Age Calculator
Calculate your exact age in years, months, and days with our precise age calculator.
HMAC Generator
Generate HMAC digests easily
Sales Tax Calculator
Easily calculate sales tax and total price with our intuitive sales tax calculator.
Hex to Binary
Convert hexadecimal code to binary effortlessly
Create Beautiful CSS Gradients Effortlessly
Generate stunning linear, radial, and conic gradients with our intuitive interface. Copy the CSS code and use it in your projects instantly.
Remove line breaks from your text
Convert multi-line text into a single continuous line with our easy-to-use tool.