How do I calculate the average by hand?

Add every value, then divide by how many values there are. For 4, 8, and 9 the sum is 21, and 21 divided by 3 gives a mean of 7. Open Show the arithmetic under the result to see the same steps on your own list.

My mean and median are far apart. Which one is right?

Both are correct arithmetic. They answer different questions. A large gap means a few values sit far out on one side. Quote the median for a typical case, such as a typical salary, and the mean when the total matters, such as budget per person.

Is there a mode when every number appears once?

No. With no repeats, no value is more common than another, so the page reports no mode. The same goes for a list where every value ties, such as 2, 2, 5, 5. When two or three values tie for the top count, the page lists all of them.

Do blank cells count as zero?

No. Blanks and text such as n/a are skipped, and the page lists each skipped entry by name. If a missed quiz earns a zero, type 0. Mixing those two up is a common way to inflate a class average.

How does the weighted average work for a GPA?

Multiply each grade point by its credit hours, add those products, and divide by total credits. Grades of 3.0, 3.7, 4.0, and 2.0 on 4, 4, 3, and 1 credits give 40.8 divided by 12, a GPA of 3.4. The unweighted mean of the same grades is 3.175.

Can I paste a column from Excel or Google Sheets?

Yes. Copy the cells and paste. Each cell lands on its own line. If the cells show thousands separators like 1,250, set the comma option to Thousands first, or each number splits in two.

Does my data leave the browser?

No. Every calculation runs on your device. Nothing is uploaded, logged, or stored.

Average Calculator - Mean, Median, Mode & Weighted Average

Row	Value	Weight	Value × weight	Share of weight
Total		12	40.8	100%

Which average answers your question

“Average” is three different numbers wearing one name. Pick by the question you are asking, not by habit. The mean is what school taught as the average, though for half the questions people ask, a different one gives the honest answer.

Your question	Use	Why
What does a typical house, salary, or wait time look like?	Median	A few huge values pull the mean away from where most people sit. The median ignores how far out the extremes go.
How much in total, shared out evenly? Splitting a bill, budgeting a monthly spend.	Mean	Mean × count gives back the exact total. No other average does.
Which size, rating, or option comes up most?	Mode	A shoe shop restocks the size people buy, not size 9.83.
Some rows count more than others. GPA, average price per share, combined class scores.	Weighted mean	A 4-credit course moves your GPA four times as much as a 1-credit lab.
Average speed over a round trip at two speeds.	Total distance ÷ total time	More hours pass at the slow speed, so the slow leg needs more weight. See the trap below.
Average yearly growth of an investment or a population.	Geometric mean	Growth compounds. Use the Mean Calculator, which has a geometric option.

Worked case: nine salaries and a founder

A nine-person startup posts a job ad saying “average salary $87,000.” Eight employees earn between $48,000 and $72,000. The founder pays themselves $310,000. Load Team salaries plus founder above to follow along.

Add everything.48,000 + 52,000 + … + 72,000 + 310,000 = 786,000
Divide by the headcount.786,000 ÷ 9 = 87,333. The ad is technically right.
Sort and take the middle. The 5th of 9 sorted salaries is 61,000. Four people earn less, four earn more.
Check the pull. Drop the founder and the mean falls to 59,500. One person moved the “average” by almost $28,000.
Read the gap. Not one of the eight employees earns $87,333. A new hire should expect something near $61,000. When the mean and median sit this far apart, quote the median, and treat a job ad quoting only the mean with suspicion.

The calculator flags this case on its own. The note under the dot plot points out the gap, and the Mean without farthest value line shows the $59,500 figure without a second calculation.

Three averages people get wrong

Averaging two averages

Class A has 20 students averaging 80. Class B has 5 students averaging 60. The combined average is not 70. Each class average has to count once per student: (20 × 80 + 5 × 60) ÷ 25 = 76. Load Two class averages in weighted mode to check. The same mistake shows up when people average store-level conversion rates or regional prices without weighting by volume.

Averaging speeds

You drive 120 km out at 60 km/h and 120 km back at 40 km/h. The average speed is not 50. The trip took 2 hours out plus 3 hours back, so 240 km ÷ 5 h = 48 km/h. You spent more time at the slow speed, and the plain mean pretends you did not.

Averaging percent changes

A stock gains 50% one year and loses 50% the next. The plain mean says 0%. Start with $100. The first year takes it to $150, the second drops the balance to $75. You lost 25%. Percent changes multiply, so their average needs the geometric mean, which works out to about −13.4% per year here.

Where this calculator falls short

Mode on measured decimals is mostly noise. Readings like 12.31 and 12.29 almost never repeat, so the page reports no mode. Round the values first if you want clusters, or read the dot plot instead.
One comma rule per list. A paste mixing 1,250 and 3,5 cannot be read both ways. Anything the page refuses shows up by name under the box, so nothing disappears quietly.
No times, dates, or fractions.1:45, 2026-03-01, and 3/4 are skipped. Convert durations to minutes and fractions to decimals first.
Precision tops out near 15 digits. Sums use compensated addition, so ten copies of 0.1 total exactly 1. Whole numbers above 9,007,199,254,740,991 lose their last digits, which matters for IDs and almost nothing else.
A million values per paste. Past a million the browser tab slows, and a spreadsheet AVERAGE or MEDIAN formula is the better tool.
No spread figures. For standard deviation, quartiles, and variance, use Number List Statistics.

Average Calculator