Confidence Interval for Slope of Regression Line Calculator
This confidence interval for slope of regression line calculator helps you estimate the true slope of a linear relationship using sample data, confidence levels, and internationally accepted statistical formulas.
- Designed for academic, research, and professional use
- Works perfectly inside WordPress
- Mobile-first and fully responsive
Calculator Inputs
Enter your sample data and statistical preferences below. Each input directly affects the accuracy of the confidence interval.
| Input | Description | Example |
|---|---|---|
| X values | Independent variable data | 1,2,3,4 |
| Y values | Dependent variable data | 2,4,5,8 |
| Confidence Level | Statistical certainty level | 95% |
| Model Year | Reference year for reporting | 2025 |
Calculation Results
The results below show the estimated regression slope and its confidence interval.
| Metric | Value |
|---|---|
| Estimated Slope (β₁) | — |
| Lower Bound | — |
| Upper Bound | — |
Visual Representation
The graph illustrates the sample data and fitted regression line.
- Dots represent observed data
- Line represents estimated regression slope
How to Interpret the Confidence Interval
The confidence interval helps you understand uncertainty in the estimated slope.
| Scenario | Interpretation |
|---|---|
| Interval excludes zero | Statistically significant relationship |
| Interval includes zero | No strong linear evidence |
- Higher confidence levels create wider intervals
- Larger samples improve precision
Use the Regression Curve Calculator to fit curves to your data, or explore the fullRegression Calculator category to access all regression analysis tools in one place.