Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Normal Distribution Calculator

Compute left-tail, right-tail, or two-tail probabilities for any normal distribution given its mean and standard deviation. Widely used in statistics, finance, and scientific research.

Mean (μ)

Standard Deviation (σ)

X Value

Tail Type

Fill in the required fields to see your result.

Probability

Confidence Interval Calculator

Computes the range of values likely to contain a true population mean at your chosen confidence level. Use it when reporting survey results, clinical trial outcomes, or any estimate derived from a sample.

Sample Mean

Sample Standard Deviation

Sample Size (n) (observations)

Confidence Level

Distribution Type

Fill in the required fields to see your result.

Key differences

	Normal Distribution Calculator	Confidence Interval Calculator
Category	Probability	Probability
Inputs required	4	5
Result	Probability	Margin of Error (±)
What it does	Compute left-tail, right-tail, or two-tail probabilities for any normal distribution given its mean and standard deviation. Widely used in statistics, finance, and scientific research.	Computes the range of values likely to contain a true population mean at your chosen confidence level. Use it when reporting survey results, clinical trial outcomes, or any estimate derived from a sample.