Midrange Calculator

The midrange formula

The midrange is the arithmetic mean of the maximum and minimum values in a data set:

midrange = (max + min) / 2

It depends on only two numbers, the two extremes, so it ignores everything in between. That makes it extremely fast to compute, but also very sensitive to outliers: a single unusually large or small value can pull the midrange far away from where most of the data sits.

Worked example

Take the data set 4, 8, 15, 16, 23, 42.

• Minimum = 4
• Maximum = 42
• Range = 42 − 4 = 38
• Midrange = (42 + 4) / 2 = 46 / 2 = 23

Notice the midrange (23) is higher than four of the six values. Because 42 is far from the rest, it drags the midrange upward, a classic sign that the data is skewed.

Midrange vs. other measures of center

Common pitfalls

• Outliers dominate. Because the midrange uses only the highest and lowest values, one typo (for example 420 instead of 42) can throw the result off completely. Always scan your data first.
• Not the same as the mean. The midrange averages two numbers; the mean averages all of them. They match only for perfectly symmetric data.
• Small samples mislead. With just a few points, the extremes are unstable, so the midrange jumps around. For robust summaries on skewed or noisy data, prefer the median.