Average Calculator
Average = sum of values / number of values.
Enter the full list of values
Enter the values that belong in the same set. Separate them clearly, and keep the same unit or score type throughout the list. Do not mix percentages with raw points unless that is exactly what the problem asks for.
Use this calculator for grades, small datasets, scores, expenses and quick summaries. If the data has strong outliers, also consider median. The average can be useful and still not tell the whole story.
What the mean represents
The average, or arithmetic mean, is the total of all values divided by the number of values. It gives a balancing point for the list. Every value contributes to the result.
Because every value counts, a very high or low value can move the average a lot. That is not a calculator mistake. It is how the mean works.
Average formula
Average = sum of values / number of values. Add every value in the list, then divide by the count of values. If the list has 5 numbers, divide by 5. If it has 12 numbers, divide by 12.
Zeros count when they are real values. A score of zero, a day with zero sales or a measurement of zero belongs in the average if it belongs in the dataset.
Finding the average of test scores
For the values 80, 90, 100 and 70, the sum is 340. There are 4 values. Divide 340 by 4 to get an average of 85.
If a zero score is added, the list becomes 80, 90, 100, 70 and 0. The sum is still 340, but the count is now 5. The average becomes 68.
Outliers can hide in the mean
The biggest mistake is leaving out zeros because they look like missing data. If zero is a real score or measurement, it must be included. If the blank means unknown, do not treat it as zero unless the rules say so.
Another mistake is using the average when the median would answer the question better. For skewed data, the mean can be pulled away from the typical value.
Average Calculator FAQ
How do I calculate an average?
Add all values in the list. Then divide by how many values are in the list. For 80, 90, 100 and 70, the sum is 340. Divide by 4 to get 85.
Make sure every value belongs to the same dataset before calculating.
Do zeros count in an average?
Yes, if zero is a real value. A zero test score, zero sales day or zero measurement changes the average and should be included.
If a blank means missing data, treat it differently. Missing and zero are not the same thing.
This is especially important for grades. A missing assignment may be blank until graded, or it may be recorded as zero by policy.
Why did one number change the average so much?
The mean uses every value. A very high or very low value can pull the result toward itself. That value is often called an outlier.
If you want a typical middle value that resists outliers better, also check the median.
The average is not wrong in that case. It is answering a different question than the one people often mean by typical.
Is average the same as mean?
In everyday calculator use, average usually means arithmetic mean. That is the sum divided by the count.
In statistics, average can be used more broadly. It may refer to mean, median or mode depending on context.
Should I round the average?
Round the final average according to the situation. For grades, follow the school or assignment rule. For quick estimates, one or two decimals may be enough.
Do not round the values before averaging unless the data was already recorded that way.
For money, grades or reports, keep enough decimal places to avoid changing the decision.