Survival Analysis
log-rank test statistical calculator
Log-rank Test Statistical Calculator
Log-Rank Test Calculator compare two independent survival curves. It is part of the Salar Cafe collection of free statistical calculators.
Quick Answer
The Log-Rank Test Statistical Calculator runs the named method with its own validated formula, inputs, intermediate results, chart and interpretation.
Survival Analysis
Log-Rank Test Calculator
Compare two independent survival curves.
Calculated result
When to use
Compare two independent survival curves.
Formula
Sum observed minus expected events across event times and standardize by its variance.
Assumptions and limits
Use the named design, correct variable scale, independent or paired structure as specified, transparent missing-data handling, and an adequate sample before interpreting inference.
Method integrity
This page uses a separate canonical calculator ID, method-specific inputs, a dedicated calculation branch, an automated fixture, and no generic fallback result.
Use Raw Data, Excel, or CSV
Upload XLSX, CSV, TSV or pasted data, review cleaning, then select the dependent, independent, grouping, paired, time, item, rater or study variables required by Log-Rank Test.
Uploaded files are processed locally in the browser. The cleaning report appears before variable dropdowns, and the selected cleaned columns are placed into this exact calculator rather than a generic fallback method.
Log-Rank Test Calculator Features
Included
Dedicated formula and calculator function
Included
Manual and browser-local spreadsheet input
Included
Visible variable roles and selected column names
Included
Method-specific chart and downloadable results
Included
Assumptions, warnings and reporting guidance
Included
Canonical URL with no synonym duplication
About the Log-Rank Test Calculator
Compare two independent survival curves. This calculator applies the displayed method to the requested inputs and reports the intermediate values used in the result.
When to Use the Log-Rank Test Calculator
Compare two independent survival curves.
How the Log-Rank Test Calculator Works
Sum observed minus expected events across event times and standardize by its variance.
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.
Assumptions and Checks
- The study design and variable scales match the named method.
- Independence, pairing, ordering, censoring, grouping or rater structure is represented correctly.
- Missing values and influential observations are reviewed before inference.
Required Inputs
- Follow-up time (required)
- Event indicator (1/0) (required)
- Independent group code (required)
- Alpha (required)
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:
- Observed Group 1
observed_group_1 - Expected Group 1
expected_group_1 - Variance
variance - Z Statistic
z_statistic - Chi Square
chi_square - P Value
p_value - Decision
decision
Log-Rank Test Calculator Example
Load the example or upload cleaned data, map variables, calculate, and review the method-specific result and chart.
| Input | Example value |
|---|---|
| Follow-up time | 2,3,4,5,6,7,8,9,10,11 |
| Event indicator (1/0) | 1,0,1,1,0,1,1,0,1,1 |
| Independent group code | 0,0,0,0,0,1,1,1,1,1 |
| Alpha | .05 |
Verified Worked Result
The packaged automated fixture produces the following checked values from the example inputs. Display rounding may differ from the full-precision browser calculation.
| Result | Verified value |
|---|---|
| Observed Group 1 | 3 |
| Expected Group 1 | 1.1607142857143 |
| Variance | 0.68845663265306 |
| Z Statistic | 2.2167203261053 |
| Chi Square | 4.9138490041686 |
| P Value | 0.026642208921783 |
| Decision | Reject the null hypothesis |
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
Review the Log-Rank Test estimate or test statistic, uncertainty or p-value where applicable, assumptions, chart and research-question interpretation.
Review the formula, units, assumptions, and result interpretation before using the calculation.
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.
How to Report the Result
Report Log-Rank Test, the analyzed variables and valid sample size, the principal estimate or statistic, degrees of freedom and p-value or confidence interval where available, assumptions, and a conclusion tied to the research question.
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 Log-Rank Test Calculator calculate?
Compare two independent survival curves.
Which formula does the Log-Rank Test Calculator use?
Sum observed minus expected events across event times and standardize by its variance.
Related Search Questions and Calculator Terms
This page answers the following closely related statistical calculator searches without creating duplicate competing URLs:
- log-rank test calculator
- online log-rank test calculator
- statistical calculator
- statistical calculators
When should I use the Log-Rank Test Statistical Calculator?
Compare two independent survival curves.
What formula does the Log-Rank Test Statistical Calculator use?
Sum observed minus expected events across event times and standardize by its variance.
Which variables does the Log-Rank Test Statistical Calculator require?
The upload panel identifies compatible variable types and shows the exact dependent, independent, grouping, paired, time, item, rater or study roles required by this method.
Can the Log-Rank Test Statistical Calculator analyze Excel or CSV data?
Yes. XLSX, CSV, TSV or pasted data are cleaned locally, then selected columns are mapped to this exact calculator and chart.