Cramér's V Calculator

Where it is used

• Teachers: A teacher checks whether the class a student is in is related to whether they passed or failed the end-of-term test.
• Small-business owners: A shop owner sees if the branch a customer visited is linked to whether they left a positive or negative review.
• HR staff: An HR officer looks at whether an employee's department is connected to whether they stayed with or left the company.

Reading Cramér's V

Cramér's V ranges from 0 (no association) to 1 (perfect association). As a rough guide, 0.1 is small, 0.3 is medium and 0.5 or above is large. It is derived from the chi-square statistic and the table size.

When should you use it?

Use this calculator when you want to know if two "category" questions are related. A category question has answers that are labels, not numbers, such as yes or no, male or female, or which branch someone visited. Cramer's V tells you how closely one category is tied to another. It works with tables of any size, so you can compare two groups or many at once. If your data is made of real numbers, like age in years or money spent, this is not the right tool for that.

What does the result mean?

The result is a single number between 0 and 1. A value near 0 means there is almost no link between your two categories. A value near 1 means they are very strongly linked, so knowing one tells you a lot about the other. For a simple two-by-two table, a common guideline is that about 0.1 is a small link, about 0.3 is a moderate link, and 0.5 or more is a strong link. Larger tables shift these marks, so treat them only as a rough guide.

Mistakes to avoid

Make sure every row has the same number of counts, or the table will not line up. Enter the actual number of people or responses in each cell, not percentages. Do not use this for number answers like age or price, because it is only for categories. Remember that a strong Cramer's V shows two things move together, but it does not prove that one causes the other. Finally, very small samples can give misleading results, so gather enough responses first.

How to use this calculator

1. Build your table: list each group as a row and each answer choice as a column, then count how many responses fall in each cell.
2. Enter the counts, putting one row on each line and separating the numbers with commas.
3. Check that every row has the same number of values, then run the calculation.
4. Read the result, a number between 0 and 1, where higher means a stronger link between the two categories.

Worked example

A cafe asks 100 customers whether they liked a new muffin, split by where they live. In town, 30 liked it and 20 did not. Out of town, 10 liked it and 40 did not. You enter "30, 20" on the first line and "10, 40" on the second line. The calculator returns a Cramer's V of about 0.41, a moderate to strong link, suggesting that where someone lives and whether they like the muffin are related.

Frequently asked questions

Related calculators

• Chi-Square Test Calculator
• Correlation Calculator (Pearson r)