Regression Slope Calculator
Enter paired X and Y values to get the least-squares regression line: its slope (m) and its intercept (b). The slope is how much Y changes per one-unit increase in X.
What this calculator does
The Regression Slope Calculator estimates your result instantly from the values you enter, using standard statistics formulas. Enter paired X and Y values to get the least-squares regression line: its slope (m) and its intercept (b). The slope is how much Y changes per one-unit increase in X. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Regression Slope Calculator
This tool fits a least-squares straight line to two comma-separated lists of numbers and reports its slope (m) and intercept (b). The slope is the estimated change in Y for each one-unit rise in X; the intercept is the fitted value of Y when X is zero.
Use it whenever you have paired data and want the coefficients of the best-fit line without building a full spreadsheet regression.
Formula & Mathematical Calculation
Calculation Method
- Compute } d=n × sx2-sx × sx
- Compute } m=(n × sxy-sx × sy) ÷ d, b=(sy-m × sx) ÷ n
Calculation Example
Enter X values of 1, 2, 3, 4 and Y values of 2, 4, 5, 8, then click Calculate.
The tool returns Slope (m) = 1.9 and Intercept (b) = 0, with the note: “The least-squares regression slope is 1.9 with intercept 0.”
Key Benefits
- Computes the least-squares slope and intercept from paired X and Y lists in one step
- Parses comma-separated values and filters out non-numeric fragments automatically
- Rounds the slope and intercept to five decimal places for fine-grained results
- Stops with a clear message when the X values have no variation, which would make the slope undefined
How to Use this Calculator
-
Enter X values
Put your independent values in the X field, comma-separated, for example 1, 2, 3, 4. -
Enter Y values
Put the same count of dependent values in the Y field, for example 2, 4, 5, 8. -
Calculate
Click Calculate to populate the Slope (m) and Intercept (b) boxes. -
Read the line
Combine the two results into the fitted line y = m times x + b using the reported values.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Regression Slope Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.