Statistical Tables · free & public domain
Pearson Correlation Critical Values (PPMC)
Critical values of Pearson’s r by sample size, for testing H₀: ρ = 0.
How to use this table
Read down to your sample size n, across to your two-tailed α. Reject H₀: ρ = 0 — that is, call the correlation significant — if |r| exceeds the value. Example: n = 20 at α = 0.05 → 0.444, so an observed r of 0.52 is significant but 0.41 is not. Indexed by n directly, so there is no d.f. conversion to get wrong.
The table
| n / two-tail α | 0.1 | 0.05 | 0.02 | 0.01 | 0.001 |
|---|---|---|---|---|---|
| 3 | 0.988 | 0.997 | 1.000 | 1.000 | 1.000 |
| 4 | 0.900 | 0.950 | 0.980 | 0.990 | 0.999 |
| 5 | 0.805 | 0.878 | 0.934 | 0.959 | 0.991 |
| 6 | 0.729 | 0.811 | 0.882 | 0.917 | 0.974 |
| 7 | 0.669 | 0.754 | 0.833 | 0.875 | 0.951 |
| 8 | 0.621 | 0.707 | 0.789 | 0.834 | 0.925 |
| 9 | 0.582 | 0.666 | 0.750 | 0.798 | 0.898 |
| 10 | 0.549 | 0.632 | 0.715 | 0.765 | 0.872 |
| 11 | 0.521 | 0.602 | 0.685 | 0.735 | 0.847 |
| 12 | 0.497 | 0.576 | 0.658 | 0.708 | 0.823 |
| 13 | 0.476 | 0.553 | 0.634 | 0.684 | 0.801 |
| 14 | 0.458 | 0.532 | 0.612 | 0.661 | 0.780 |
| 15 | 0.441 | 0.514 | 0.592 | 0.641 | 0.760 |
| 16 | 0.426 | 0.497 | 0.574 | 0.623 | 0.742 |
| 17 | 0.412 | 0.482 | 0.558 | 0.606 | 0.725 |
| 18 | 0.400 | 0.468 | 0.543 | 0.590 | 0.708 |
| 19 | 0.389 | 0.456 | 0.529 | 0.575 | 0.693 |
| 20 | 0.378 | 0.444 | 0.516 | 0.561 | 0.679 |
| 21 | 0.369 | 0.433 | 0.503 | 0.549 | 0.665 |
| 22 | 0.360 | 0.423 | 0.492 | 0.537 | 0.652 |
| 23 | 0.352 | 0.413 | 0.482 | 0.526 | 0.640 |
| 24 | 0.344 | 0.404 | 0.472 | 0.515 | 0.629 |
| 25 | 0.337 | 0.396 | 0.462 | 0.505 | 0.618 |
| 26 | 0.330 | 0.388 | 0.453 | 0.496 | 0.607 |
| 27 | 0.323 | 0.381 | 0.445 | 0.487 | 0.597 |
| 28 | 0.317 | 0.374 | 0.437 | 0.479 | 0.588 |
| 29 | 0.311 | 0.367 | 0.430 | 0.471 | 0.579 |
| 30 | 0.306 | 0.361 | 0.423 | 0.463 | 0.570 |
| 32 | 0.296 | 0.349 | 0.409 | 0.449 | 0.554 |
| 34 | 0.287 | 0.339 | 0.397 | 0.436 | 0.539 |
| 36 | 0.279 | 0.329 | 0.386 | 0.424 | 0.525 |
| 38 | 0.271 | 0.320 | 0.376 | 0.413 | 0.513 |
| 40 | 0.264 | 0.312 | 0.367 | 0.403 | 0.501 |
| 45 | 0.248 | 0.294 | 0.346 | 0.380 | 0.474 |
| 50 | 0.235 | 0.279 | 0.328 | 0.361 | 0.451 |
| 60 | 0.214 | 0.254 | 0.300 | 0.330 | 0.414 |
| 70 | 0.198 | 0.235 | 0.278 | 0.306 | 0.385 |
| 80 | 0.185 | 0.220 | 0.260 | 0.286 | 0.361 |
| 90 | 0.174 | 0.207 | 0.245 | 0.270 | 0.341 |
| 100 | 0.165 | 0.197 | 0.232 | 0.256 | 0.324 |
| 150 | 0.135 | 0.160 | 0.190 | 0.210 | 0.266 |
| 200 | 0.117 | 0.139 | 0.164 | 0.182 | 0.231 |
Indexed by sample size n (not d.f.), with a 0.001 column and n to 200.
How these values were produced
r = t/√(t² + d.f.) with d.f. = n − 2 — the exact equivalence between the t test and the correlation test (SciPy 1.17).
Every one of these 210 values was computed from the underlying distribution — none was transcribed from a printed table. Values of this kind are mathematical facts: they come out the same for anyone who computes them correctly.
Need the test run rather than the critical value looked up? The Proof Workbench computes t, r, χ² and ANOVA in your browser with assumption checks and a re-verifiable receipt.
Use it freely
This table is dedicated to the public domain under CC0 1.0. No attribution required, no signup, no limits — copy it into a lecture, a textbook, or your own site. A link back is welcome but not asked for.