Average, Median & Mode

Everyday & learning

All three averages at once, because the gap between them is the point.

Median
22,750
The middle value — half are above, half below
Mean
75,750
Mode
—
Count
8

Separate with commas, spaces or new lines.

These numbers are
Every measure
Count8
Sum606,000
Mean75,750
Median22,750
Modenone — every value appears once
Minimum18,000
Maximum450,000
Range432,000
Std deviation (sample)151,247.6682
Variance22,875,857,142.8572
Q120,625
Q325,500
Interquartile range4,875
Possible outliers

450,000

Treated as a SAMPLE: the variance divides by n − 1 (Bessel’s correction), which estimates the spread of the wider population these came from. Switch to population if these numbers are the whole set you care about — on a handful of values the two answers differ noticeably.
The mean sits well ABOVE the median, so a few large values are pulling it up. The median is the better description of a typical value here — this is why average salary figures usually overstate what most people earn.
1 value is more than 1.5 × the interquartile range outside the quartiles, which is the usual rule of thumb for an outlier. That is a prompt to look at them, not a reason to delete them.

How to use

What it's for

Find the typical value in a list of numbers — salaries, prices, scores — with the median, the mean and the mode side by side.

Before you start

Have the numbers ready to type or paste, such as a column copied from a spreadsheet. If some numbers should count more than others, have their weights too.

  1. Put in your numbers

    Press Clear to empty the sample, then type or paste into Numbers. Separate them with commas, spaces or new lines — one per line is simplest when pasting from a spreadsheet.

  2. Add weights, only if you need them

    Press Use weights only when some numbers count more than others, such as subjects with more units. Then type one weight per number, in the same order, in Weights — one per number.

  3. Press Calculate

    Press Calculate. The answer already updates as you type; the button brings it into view.

  4. Say what the numbers are

    Under These numbers are, pick A sample of something larger when they are a few taken from a bigger group, or The whole set when they are everything you care about. This changes only the spread figures, not the averages.

  5. Read every measure

    Every measure lists the lowest, the highest, the spread and more. Possible outliers names any value far from the rest — a prompt to check it, not to delete it.

Reading the result

  • Median: the big number — the middle value once the numbers are sorted, so half are above it and half below.
  • Mean: the usual average, the total divided by the count. A big gap between it and the median means a few extreme numbers are pulling it.
  • Mode: the value that appears most often. A dash, or none — every value appears once, means no value repeats.
  • Count: how many numbers were read. Check it matches what you typed.

If it goes wrong

  • Count is higher than you expected: a comma inside a number, as in 18,000, splits it into two numbers. Type 18000 instead.
  • Something you typed is listed under Skipped: it could not be read as a number, such as a word or a unit, so it was left out of every figure. Fix it or delete it.
  • An error says the values and weights do not match: each number needs exactly one weight. Fix the weights, or press Use weights again to switch them off.

What this is

Three different numbers are called “the average”, and the gap between them is the information.

The mean is the total over the count. The median is the middle value once sorted. The mode is whichever occurs most often.

On Philippine salary data the mean sits well above the median, because a handful of very large values drag it up. Quote the mean alone and you have described a country almost nobody lives in. So the median is the figure at the top here, with the mean immediately beside it so the gap is visible.

There is a second choice that changes the answer: sample or population. Dividing by n describes exactly the numbers in front of you. Dividing by n − 1 estimates the spread of a wider population you sampled. On five values that is a 12% difference. Most calculators pick one without saying. This one asks, and labels the answer.

Questions

Which one is "the average"?

All three are, which is why all three are shown. The mean is the total divided by the count. The median is the middle value once they are sorted. The mode is whichever value occurs most often. On a tidy, symmetric set they land close together; when they do not, the gap is the interesting part.

Why is the median the headline figure and not the mean?

Because on the kind of data people paste — salaries, prices, response times — a few very large values pull the mean upward and it stops describing anybody. Average salary figures are the standard example: the mean can sit above what three quarters of people earn. The mean is shown right beside the median so you can see the gap rather than have it hidden by a choice somebody else made.

Sample or population — which should I pick?

Sample if these numbers are a subset of a larger group you are drawing conclusions about; population if they are the entire set you care about. It genuinely changes the answer: sample variance divides by n − 1 (Bessel's correction) and population divides by n, which on a handful of values differs by ten per cent or more. Most calculators pick one without telling you. This one asks, defaults to sample, and labels the result.

Why does it say there is no mode?

Because every value appeared exactly once. Listing all of them as modes would be technically defensible and practically useless. Equally, a set can have two modes — this reports both rather than picking one, because "the mode" as a single figure forces a wrong answer whenever there is a tie.

What counts as an outlier here?

A value more than 1.5 times the interquartile range beyond the first or third quartile — the usual rule of thumb, and the same one that draws the whiskers on a box plot. It is a prompt to look at those values, not a licence to delete them. Quartiles use the R type-7 definition, which is what Excel's QUARTILE and NumPy's default both use; there are several accepted methods and they disagree on small sets, so it matters which one is named.

Do the weights affect the median too?

No, only the mean. A weighted median does exist, but it is a different and less standardised measure, and returning one under the label "median" would mislead more than it helped. The page says so whenever weights are in use.

The maths

Eight salaries, one director
Median₱22,750
Mean₱75,750
Earning above the mean1 of 8
Std dev: sample ÷ (n−1)≠ population ÷ n
Quartiles: R type-7, as Excel QUARTILE and NumPy use. Outlier: beyond 1.5 × IQR outside the quartiles.

Keep going

Important

Runs entirely in your browser; nothing is transmitted. Standard deviation defaults to the sample formula (dividing by n − 1) and the page says which one it used. Quartiles use the R type-7 definition, as Excel and NumPy do. Nothing you type here is sent to our servers — the calculation runs entirely in your browser.