How to use the coefficient of determination calculator
Convert r to R² and explained variance. Enter correlation r in the field above; the r², variance explained, unexplained are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- r — Correlation r
Worked example
With correlation r = 0.8, the calculator gives r² ≈ 0.64; variance explained ≈ 64 %; unexplained ≈ 36 %.
Frequently asked questions
What is the formula for the coefficient of determination calculation?
R² = r × r. Variance explained (%) = 100 × [R²]. Unexplained (%) = 100-[Variance explained]. Here r is correlation r.
What inputs do I need for the coefficient of determination calculator?
You need correlation r. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.