T-Score Calculator

This t-score calculator works out the one-sample t statistic, the figure statisticians and researchers use to test whether a sample mean differs meaningfully from a known or hypothesised population mean when the population's true standard deviation is not known. You enter four figures: the sample mean, the population mean you are testing against, the sample standard deviation, and the sample size (n). From these, the calculator returns the t value, the degrees of freedom, always n minus 1 for a one-sample test, and the standard error, calculated as the sample standard deviation divided by the square root of n. The t value shows how many standard errors your sample mean sits from the hypothesised mean, so the further it is from zero, the stronger the evidence that the true mean differs from what you assumed. To reach a conclusion, compare that t value against a critical value from the t distribution, or convert it to a p-value, using the degrees of freedom shown, since the t distribution has heavier tails than the normal distribution and suits small samples where variability is estimated rather than known. Results update instantly as you change any input, making this a quick way to check a hand calculation, mark student work, or run a fast hypothesis test. It assumes valid numbers and a genuine one-sample comparison; two-sample or paired data need a different test.

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