Gratuit en LigneCalculatrices
Z-Score Calculator
Calculate z-scores and find probabilities for normal distributions. Convert raw scores to z-scores or find the probability area under the curve.
z score calculatorz-score calculatorstandard score calculatornormal distribution z scorez score to probability
Fonctionnalités Clés — Z-Score Calculator
Z-score from raw value, mean, and standard deviation
Probability below, above, and within z
Find probability from z-score
Standard normal CDF calculation
Common critical values reference
Pourquoi Utiliser Cet Outil — Z-Score Calculator
Gratuit en Ligne Z score calculatorZ-score calculator — pour TousRapide & Facile Standard score calculatorNormal distribution z score — 100% GratuitGratuit en Ligne Z score to probabilityCalculate z score — pour Tous
Confidentialité d'abord
Tout le traitement se fait dans votre navigateur. Vos données ne quittent jamais votre appareil.
Ultra Rapide
Obtenez des résultats instantanés sans temps d'attente. Pas de délais serveur.
Fonctionne Partout
Utilisez sur tout appareil — ordinateur, tablette ou téléphone. Aucun téléchargement nécessaire.
Questions Fréquemment Posées — Z-Score Calculator
What is a z-score?
A z-score (standard score) tells you how many standard deviations a value is above or below the mean. Z = (X − μ) / σ. A z-score of 0 means the value equals the mean. Z = 1 means one standard deviation above the mean. Z = −2 means two standard deviations below.
What does a z-score of 1.96 mean?
A z-score of 1.96 is the critical value for a 95% confidence interval. It means the value is 1.96 standard deviations above the mean. In a normal distribution, 95% of data falls within ±1.96 standard deviations of the mean, leaving 2.5% in each tail.
How do I interpret a negative z-score?
A negative z-score means the value is below the mean. For example, z = −1.5 means the value is 1.5 standard deviations below the mean. The probability of being below this value is the same as the probability of being above z = +1.5.