Average Calculator — Mean, Median, Sum and Count
An average calculator summarises a list of numbers: the mean, the median, the total, and how many values you entered.
Average Calculator
What this tool does
Enter any list of numbers and the tool reports the count, sum, mean (the usual “average”), median (the middle value), smallest and largest values. It is useful for test scores, prices, measurements and survey results.
How to use it, step by step
- Type your numbers, separated by commas or spaces.
- Press Calculate.
- Read the mean for the overall level, and the median to check whether a few extreme values are pulling the mean up or down.
Worked example
Scores of 70, 80, 90 and 100 have a sum of 340 and a count of 4, so the mean is 340 ÷ 4 = 85. The median is the middle of the sorted list: with four values, it is the average of 80 and 90, which is also 85 in this case. If one score were 40 instead of 100, the mean would fall to 70 while the median would stay at 75, showing why both measures are worth looking at.
Common mistakes
- Confusing mean and median: the mean uses every value; the median only describes the middle. They can differ a lot when values are uneven.
- Forgetting a value: one missing number changes both the sum and the count, so count your inputs first.
- Mixing units: do not average centimetres with metres, or minutes with hours, without converting first.
Frequently asked questions
What is the mean?
The mean is the sum of all values divided by how many values there are.
What is the median?
The median is the middle value when numbers are sorted. With an even count, it is the average of the two middle values.
Can the average be a decimal?
Yes. A mean of 85.5 is perfectly normal even if every input is a whole number.
What if I enter a word by mistake?
Non-numeric entries are ignored, but it is best to check your list so you do not silently lose a value.