Normal Distribution Calculator
Calculate Z-scores and solve bell curve probabilities instantly. Enter your Mean and Standard Deviation, then select your formula mode (Left Tail, Right Tail, or Interval) for exact statistical results.
Last updated: February 24, 2026
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Distribution Parameters
Probability Query
Results
Exact Probability Area
Calculated Z-Scores
The Bell Curve Probability Areas
Calculates the total mathematical area under the curve from negative infinity up to a specific x value. Expressed formally as P(X < x).
Represents the area greater than a specific value, continuing towards positive infinity. It represents the inverse remainder of a Left Tail equation: P(X > x) = 1 - P(X < x).
Finds the exclusive probability of an event landing strictly between two established bounds, x1 and x2. Represents the core mass of the bell curve.
The total probability of an outcome landing in either extreme tail (less than x1 OR greater than x2), completely ignoring the middle distribution section.
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