T Tests
Welch Independent Samples T Test Calculator
Welch Independent Samples T Test Calculator compare two means without assuming equal variances.
T Tests
Welch Independent Samples T Test Calculator
Compare two means without assuming equal variances.
Formula
Welch independent-samples t test: t = (mean A - mean B) / sqrt(sA^2/nA + sB^2/nB), with Welch-Satterthwaite degrees of freedom.
About the Welch Independent Samples T Test Calculator
Compare two means without assuming equal variances. T procedures compare means while estimating sampling variability from observed data and using the appropriate Student t degrees of freedom.
How the Welch Independent Samples T Test Calculator Works
Welch independent-samples t test: t = (mean A - mean B) / sqrt(sA^2/nA + sB^2/nB), with Welch-Satterthwaite degrees of freedom.
The calculation runs in your browser. Submitted values are validated for the required numeric range, data shape, units, and method-specific restrictions before a result is shown.
Required Inputs
- Group A data (required)
- Group B data (required)
- Alpha (required)
- Alternative hypothesis (required) Options: Two-tailed, Greater than, Less than
Results Reported
The result panel shows the final answer together with the intermediate quantities needed to audit the calculation. Depending on this method, reported values include:
n_an_bmean_amean_bmean_differencestandard_errordft_statisticp_valuedecision
Welch Independent Samples T Test Calculator Example
Use the example data button to load a known sample, then calculate and review the statistic, p-value or estimate, and interpretation.
| Input | Example value |
|---|---|
| Group A data | 12,14,15,16,18 |
| Group B data | 10,11,13,13,14 |
| Alpha | 0.05 |
| Alternative hypothesis | two |
How to Use the Calculator
- Confirm that the calculator title and method match the quantity, test, conversion, or planning question you need to solve.
- Enter values with compatible units and the requested sample, group, matrix, count, date, or option format.
- Select Example Data to inspect a valid input layout, or enter your own values and select Calculate.
- Review the result table, formula, worked substitutions, warnings, and interpretation rather than using only the headline number.
- Use Copy Result or Download CSV when you need a reusable record of the displayed calculation.
Understanding the Result
Choose paired, pooled independent, Welch, or one-sample analysis to match the design; these methods are not interchangeable.
Keep the entered values, units, selected options, and any warning shown beside the result. For a hypothesis test, report the statistic, degrees of freedom where applicable, p-value, alpha level, effect size, and decision. For an estimate or conversion, report the formula convention and final unit.
Accuracy and Limitations
The calculator keeps full browser precision during calculation and rounds only for display. Accuracy still depends on correct inputs and on whether the displayed model represents the real problem. Educational calculators cannot replace required professional review, current official rules, field measurements, laboratory methods, or specialist statistical software where those are necessary.
Frequently Asked Questions
What does the Welch Independent Samples T Test Calculator calculate?
Compare two means without assuming equal variances.
Which formula does the Welch Independent Samples T Test Calculator use?
Welch independent-samples t test: t = (mean A - mean B) / sqrt(sA^2/nA + sB^2/nB), with Welch-Satterthwaite degrees of freedom.
What input does this calculator need?
The calculator form shows the required values and validates them before calculating.
Are the formulas visible?
Yes. Each calculator displays its method, assumptions, and interpretation unless disabled by the site administrator.