What this calculator does
T-statistic (one or two sample) works out how many standard errors a sample mean, or the gap between two means, is from the reference value. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
The inputs explained
| Field | What to enter |
|---|---|
| Test type | Choose from One sample vs a reference mean, Two independent samples. |
| Sample 1 mean | A number. Starts at 52. |
| Sample 1 standard deviation | A number. Starts at 8. |
| Sample 1 size | A number. Starts at 25. |
| Reference mean (μ), one-sample only | A number. Starts at 50. |
| Sample 2 mean, two-sample only | A number. Starts at 47. |
| Sample 2 standard deviation, two-sample only | A number. Starts at 9. |
| Sample 2 size, two-sample only | A number. Starts at 22. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with sample 1 mean
Every other input is held at the calculator’s starting values while sample 1 mean varies. Select any row to load that scenario into the calculator.