The Chi Square Table gives you critical values for the chi-square distribution. Use it to decide if your calculated chi-square statistic is significant in hypothesis testing.
Students, teachers, and researchers rely on this table for goodness-of-fit tests, tests of independence, and variance analysis. Find critical values quickly by degrees of freedom and significance level (alpha).
What Is a Chi Square Table?
A Chi Square Table lists critical values for the chi-square distribution. These values help you decide if your test results are statistically significant.
The chi-square distribution is used when you compare observed data to expected data. It is always positive and skewed to the right.
Real-world example
In a survey, you expect equal votes for three options. After collecting data, you calculate a chi-square statistic. The table tells you if the difference is due to chance or real preference.
This table is essential for chi-square goodness-of-fit tests and tests of independence in statistics.
How to Use a Chi Square Table
A Chi Square Table gives critical values for the right tail of the chi-square distribution. Use it to compare your calculated chi-square statistic to the table value.
Step 1: Calculate the degrees of freedom (df). For goodness-of-fit: df = number of categories − 1. For test of independence: df = (rows − 1) × (columns − 1).
Step 2: Choose your significance level (alpha). Common choices: 0.05 or 0.01.
Step 3: Find the row for your df in the left column.
Step 4: Move across to the column for your alpha (example: 0.05). Step 5: Read the number in that cell. This is your critical value.
Step 6: Compare: If your calculated chi-square > critical value, reject the null hypothesis.
The table shows right-tail probabilities only. For most tests, this is what you need.
Chi Square Critical Value Table
| df | 0.2 | 0.1 | 0.05 | 0.04 | 0.03 | 0.025 | 0.02 | 0.01 | 0.005 | 0.0005 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1.642 | 2.706 | 3.841 | 4.218 | 4.709 | 5.024 | 5.412 | 6.635 | 7.879 | 12.116 |
| 2 | 3.219 | 4.605 | 5.991 | 6.424 | 6.962 | 7.378 | 7.824 | 9.210 | 10.597 | 15.202 |
| 3 | 4.642 | 6.251 | 7.815 | 8.292 | 8.883 | 9.348 | 9.837 | 11.345 | 12.838 | 17.731 |
| 4 | 5.989 | 7.779 | 9.488 | 10.001 | 10.633 | 11.143 | 11.668 | 13.277 | 14.860 | 20.092 |
| 5 | 7.289 | 9.236 | 11.070 | 11.618 | 12.295 | 12.833 | 13.388 | 15.086 | 16.750 | 22.307 |
| 6 | 8.558 | 10.645 | 12.592 | 13.175 | 13.892 | 14.449 | 15.033 | 16.812 | 18.548 | 24.433 |
| 7 | 9.803 | 12.017 | 14.067 | 14.681 | 15.432 | 16.013 | 16.622 | 18.475 | 20.278 | 26.510 |
| 8 | 11.030 | 13.362 | 15.507 | 16.151 | 16.936 | 17.535 | 18.168 | 20.090 | 21.955 | 28.560 |
| 9 | 12.242 | 14.684 | 16.919 | 17.591 | 18.406 | 19.023 | 19.679 | 21.666 | 23.589 | 30.585 |
| 10 | 13.442 | 15.987 | 18.307 | 19.005 | 19.851 | 20.483 | 21.161 | 23.209 | 25.188 | 32.591 |
| 11 | 14.631 | 17.275 | 19.675 | 20.399 | 21.273 | 21.920 | 22.618 | 24.725 | 26.757 | 34.582 |
| 12 | 15.812 | 18.549 | 21.026 | 21.774 | 22.676 | 23.337 | 24.054 | 26.217 | 28.300 | 36.561 |
| 13 | 16.985 | 19.812 | 22.362 | 23.133 | 24.062 | 24.736 | 25.472 | 27.688 | 29.819 | 38.528 |
| 14 | 18.151 | 21.064 | 23.685 | 24.478 | 25.434 | 26.119 | 26.873 | 29.141 | 31.319 | 40.484 |
| 15 | 19.311 | 22.307 | 24.996 | 25.812 | 26.794 | 27.488 | 28.259 | 30.578 | 32.801 | 42.431 |
| 16 | 20.465 | 23.542 | 26.296 | 27.133 | 28.141 | 28.845 | 29.633 | 32.000 | 34.267 | 44.370 |
| 17 | 21.615 | 24.769 | 27.587 | 28.445 | 29.477 | 30.191 | 30.995 | 33.409 | 35.718 | 46.301 |
| 18 | 22.760 | 25.989 | 28.869 | 29.747 | 30.803 | 31.526 | 32.346 | 34.805 | 37.156 | 48.225 |
| 19 | 23.900 | 27.204 | 30.144 | 31.042 | 32.123 | 32.852 | 33.687 | 36.191 | 38.582 | 50.143 |
| 20 | 25.038 | 28.412 | 31.410 | 32.328 | 33.437 | 34.170 | 35.020 | 37.566 | 39.997 | 52.056 |
| 21 | 26.171 | 29.615 | 32.671 | 33.607 | 34.742 | 35.479 | 36.343 | 38.932 | 41.401 | 53.964 |
| 22 | 27.301 | 30.813 | 33.924 | 34.878 | 36.042 | 36.781 | 37.659 | 40.289 | 42.796 | 55.868 |
| 23 | 28.429 | 32.007 | 35.172 | 36.142 | 37.338 | 38.076 | 38.968 | 41.638 | 44.181 | 57.767 |
| 24 | 29.553 | 33.196 | 36.415 | 37.401 | 38.629 | 39.364 | 40.270 | 42.980 | 45.559 | 59.663 |
| 25 | 30.675 | 34.382 | 37.652 | 38.655 | 39.915 | 40.646 | 41.566 | 44.314 | 46.928 | 61.554 |
| 26 | 31.795 | 35.563 | 38.885 | 39.904 | 41.197 | 41.923 | 42.858 | 45.642 | 48.290 | 63.442 |
| 27 | 32.912 | 36.741 | 40.113 | 41.149 | 42.475 | 43.195 | 44.145 | 46.963 | 49.645 | 65.327 |
| 28 | 34.027 | 37.916 | 41.337 | 42.390 | 43.749 | 44.461 | 45.427 | 48.278 | 50.993 | 67.208 |
| 29 | 35.139 | 39.087 | 42.557 | 43.627 | 45.019 | 45.722 | 46.704 | 49.588 | 52.336 | 69.086 |
| 30 | 36.250 | 40.256 | 43.773 | 44.860 | 46.285 | 46.979 | 47.976 | 50.892 | 53.672 | 70.961 |
| 31 | 37.358 | 41.422 | 44.985 | 46.089 | 47.547 | 48.232 | 49.243 | 52.191 | 55.003 | 72.832 |
| 32 | 38.465 | 42.585 | 46.194 | 47.315 | 48.805 | 49.480 | 50.506 | 53.486 | 56.328 | 74.700 |
| 33 | 39.569 | 43.745 | 47.400 | 48.537 | 50.060 | 50.725 | 51.766 | 54.776 | 57.648 | 76.565 |
| 34 | 40.672 | 44.903 | 48.602 | 49.756 | 51.311 | 51.966 | 53.021 | 56.061 | 58.964 | 78.427 |
| 35 | 41.772 | 46.059 | 49.802 | 50.972 | 52.559 | 53.203 | 54.273 | 57.342 | 60.275 | 80.286 |
| 40 | 46.979 | 51.805 | 55.758 | 56.943 | 58.365 | 59.342 | 60.436 | 63.691 | 66.766 | 88.379 |
| 45 | 52.106 | 57.505 | 61.656 | 62.902 | 64.401 | 65.410 | 66.554 | 69.957 | 73.166 | 96.217 |
| 50 | 57.153 | 63.167 | 67.505 | 68.796 | 70.364 | 71.420 | 72.613 | 76.154 | 79.490 | 103.875 |
| 55 | 62.129 | 68.796 | 73.311 | 74.645 | 76.270 | 77.380 | 78.611 | 82.292 | 85.749 | 111.398 |
| 60 | 67.053 | 74.397 | 79.082 | 80.457 | 82.138 | 83.298 | 84.580 | 88.379 | 91.952 | 118.786 |
| 65 | 71.931 | 79.973 | 84.821 | 86.237 | 87.975 | 89.177 | 90.498 | 94.422 | 98.105 | 126.032 |
| 70 | 76.764 | 85.527 | 90.531 | 91.988 | 93.785 | 95.023 | 96.383 | 100.425 | 104.215 | 133.136 |
| 75 | 81.562 | 91.057 | 96.217 | 97.715 | 99.570 | 100.839 | 102.238 | 106.393 | 110.286 | 140.109 |
| 80 | 86.329 | 96.578 | 101.879 | 103.418 | 105.330 | 106.629 | 108.066 | 112.329 | 116.321 | 146.955 |
| 85 | 91.061 | 102.079 | 107.522 | 109.102 | 111.070 | 112.399 | 113.874 | 118.136 | 122.271 | 153.669 |
| 90 | 95.758 | 107.565 | 113.145 | 114.766 | 116.791 | 118.136 | 119.647 | 124.116 | 128.299 | 160.251 |
| 95 | 100.422 | 113.038 | 118.752 | 120.414 | 122.495 | 123.858 | 125.396 | 129.973 | 134.300 | 166.701 |
| 100 | 105.053 | 118.498 | 124.342 | 126.035 | 128.164 | 129.561 | 131.126 | 135.807 | 140.169 | 173.022 |
Chi Square Table Examples
These examples show how to use the chi square table to find critical values and interpret test results.
Example 1: Goodness-of-fit test (two categories)
You roll a die 60 times. You expect each face to appear 10 times. Calculated chi-square = 8.4. Degrees of freedom: df = 6 − 1 = 5. Significance level: alpha = 0.05.
Look in row df=5, column alpha=0.05. Critical value ≈ 11.070.
Since 8.4 < 11.070, fail to reject the null hypothesis. The die appears fair.
Example 2: Test of independence (2×3 table)
You survey 200 people on preferred drink by age group. Calculated chi-square = 12.6. df = (2−1) × (3−1) = 2. Alpha = 0.01.
Row df=2, column alpha=0.01. Critical value ≈ 9.210.
Since 12.6 > 9.210, reject the null hypothesis. Preference depends on age group.
Example 3: Small sample variance test
You test if population variance equals 25 using n=10 observations. Calculated chi-square = 18.2. df = 10 − 1 = 9. Alpha = 0.05 (two-tailed test).
For two-tailed, use alpha/2 = 0.025 for upper tail. Critical value (upper) ≈ 19.023. Lower critical value ≈ 2.700 (from alpha=0.975 column if available, or note symmetry).
Since 18.2 is between lower and upper, fail to reject the null.
Use these steps to apply the chi square table in your own problems.
Common Mistakes When Using a Chi Square Table
Many people make these errors when reading a chi square table. Avoid them for accurate hypothesis testing.
- Using the wrong degrees of freedom. Always calculate df correctly: categories − 1 for goodness-of-fit, (rows − 1) × (columns − 1) for independence.
- Looking at the wrong tail. The standard chi square table shows right-tail critical values. Most tests need the upper tail.
- Choosing the wrong alpha level. Use 0.05 or 0.01 as specified in your problem. Do not mix them.
- Forgetting two-tailed adjustments. For two-tailed tests (rare in chi-square), split alpha (use alpha/2 for each tail).
- Misreading the row or column. Double-check the df row and alpha column before taking the value.
- Comparing the wrong way. Reject the null only if calculated chi-square is greater than the critical value (not less).
Review these points before you finish any chi-square test.