The midrange is the average of a data set's highest and lowest values — (max + min) / 2 — marking the midpoint of its span. It's a quick measure of center, but because it uses only the two extremes it's very sensitive to outliers. This tool also reports the min, max and range.
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: the midrange definition, recomputed in code.
The formula
Find the smallest and largest numbers in the set, add them, and halve the total — that's the midrange. The values in between don't change it. The range, the maximum minus the minimum, measures the spread. Together they summarise where the data is centred and how widely it spreads, in two quick numbers.
Worked example — 2, 4, 4, 4, 5, 5, 7, 9
The midrange is 5.5 and the range is 7. Notice the mean of this set is 5 and the median is 4.5 — the midrange differs because it ignores everything except the 2 and the 9. For 10, 20, 30 the midrange is 20, and for 3, 7, 1, 9, 5 it's 5.
Frequently Asked Questions
The average of the highest and lowest values: (max + min)/2. For 2…9 that's (2+9)/2 = 5.5.
Add the smallest and largest, divide by 2. Only the extremes matter. 10,20,30 → 20.
Mean uses all values (sum/count); median is the middle; midrange uses only min and max.
It depends entirely on the two extremes, so one stray value shifts it a lot. Median is steadier.
Maximum minus minimum — the spread. For 2…9 it's 7. Midrange centers; range spreads.