Calculadora de escore Z
Converta escores brutos em escore Z e percentil
Your Data
Exemplos rápidos
Common Z-Score Reference
Results
Assumes an approximately normal distribution
Como calculamos isto
Z-Score
E se?
Cada linha é recalculada com os seus valores atuais. Toque numa linha para a aplicar.
Comparar dois planos
Enter score, mean, and deviation
Fill in your raw score, the mean, and the standard deviation above
Z-Score Calculator FAQ
What is a z-score?
A z-score (standard score) tells you how many standard deviations a raw score is away from the population mean. z = (x − μ) ÷ σ. A z of +1.5 means the score is 1.5 standard deviations above the mean; a negative z means below the mean.
How do I turn a z-score into a percentile?
The percentile is the area under the standard normal curve to the left of z, written Φ(z). For example Φ(1.5) ≈ 0.9332, so z = 1.5 is roughly the 93rd percentile. This calculator computes Φ(z) automatically.
What do I use for μ and σ?
Use the mean and standard deviation of the reference group you are comparing against — for example the class average and its standard deviation on an exam. If only a sample is available, the sample mean and sample standard deviation are commonly used as estimates.
Can a z-score be greater than 3 or less than −3?
Yes. Z-scores have no fixed bounds; ±3 just covers about 99.7% of a normal distribution. Very large |z| means the value is extreme relative to the reference group, or that the distribution is not close to normal.
Related Statistics Calculators
Calculadora de Idade
Calcule sua idade exata em anos, meses, dias, horas e minutos com nossa calculadora de idade precisa
Calculadora de Datas
Calcule diferenças entre datas, adicione ou subtraia dias, semanas, meses e anos a qualquer data
Calculadora de Porcentagem
Calcule porcentagens, aumento percentual, diminuição e porcentagem de um número