Normal CDF Calculator
Calculate probabilities for normal distributions (normalcdf) with step-by-step solutions
Parameters
Quick Examples:
Result
Common Z-Score Values
| Confidence Level | α (two-tailed) | Z-score | P(Z < z) |
|---|---|---|---|
| 90% | 0.10 | 1.645 | 0.9500 |
| 95% | 0.05 | 1.960 | 0.9750 |
| 99% | 0.01 | 2.576 | 0.9950 |
| 99.9% | 0.001 | 3.291 | 0.9995 |
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About Normal CDF Calculator - Normal Distribution Probability
Calculate cumulative probabilities for normal distributions. Find areas under the curve between any two values or from negative infinity.
Our **Normal CDF Calculator** computes probabilities for normal (Gaussian) distributions. Enter your bounds, mean, and standard deviation to find the area under the curve. For inverse calculations, use our Inverse Normal Calculator.
The cumulative distribution function (CDF) gives P(X ≤ x), the probability that a random variable is less than or equal to a given value. This calculator handles any normal distribution, not just standard normal.
Essential for statistics students and professionals working with normally distributed data. Calculate probabilities between any two points, find percentiles, and understand the bell curve.
Key Features
Why Use This Tool?
Common Use Cases
Statistics: Finding probabilities and percentiles.
Quality Control: Process capability analysis.
Finance: Risk assessment calculations.
Research: Data analysis and inference.
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How to Use
Enter lower and upper bounds
Set mean (μ) and standard deviation (σ)
Click Calculate
View probability and z-scores
Interpret results