Relative Frequency Calculator

What Relative Frequency Measures

Relative frequency is how often a value appears compared with the size of the whole dataset. It is also called experimental or empirical probability. Divide the count of a value by the total number of observations:

$$\text{relative frequency} = \frac{\text{frequency}}{n}$$

The result is a fraction between 0 and 1. Multiply by 100 to report a percentage. Related tools: Frequency Distribution Calculator and Probability Calculator.

Cumulative Relative Frequency

Cumulative relative frequency adds each row's relative frequency to all previous rows. The last row should equal 1, which means 100% of the data has been accounted for. This running total is useful for percentiles and for seeing how quickly a distribution fills in.

Ungrouped vs Grouped Data

Ungrouped mode counts each distinct value. Grouped mode bins values into equal-width intervals from a start value. Use grouped mode when there are many unique numbers or when the data is continuous. You can also chart the table with the Pie Chart Generator.

Example

Ten quiz scores include four 72s. The relative frequency of 72 is $4/10 = 0.40$, or 40%. If 85 appears three times, its relative frequency is 0.30, and the cumulative relative frequency after both values (sorted) is 0.70.

Frequently Asked Questions

How is relative frequency different from theoretical probability?

Theoretical probability comes from a model, such as 1/6 for a fair die. Relative frequency comes from observed counts. With more trials, relative frequency usually moves closer to the theoretical value.

Can relative frequency be greater than 1?

No. Each relative frequency is a share of the sample, so values stay between 0 and 1. The cumulative relative frequency of the last row should be 1.

When should I use grouped relative frequency?

Use grouped bins when unique values are numerous or continuous, such as heights or times. Ungrouped tables work better for a small set of distinct categories or scores.

How do I convert relative frequency to a percentage?

Multiply the relative frequency by 100. A relative frequency of 0.25 is 25%.

What if my dataset has repeated values?

Repeats increase that value's frequency. The calculator groups identical numbers automatically in ungrouped mode and reports one row per distinct value.

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