Average Calculator
Average Calculator adds all entered numbers and divides by how many values were provided. The arithmetic mean uses every observation equally and can be pulled strongly by outliers. It is not always the most representative summary for skewed data, rates with different denominators, or values that need weights.
Runs locally — files stay on your deviceWhat is the average of 10, 20, and 30?
The arithmetic mean is 20.
Formula: (10 + 20 + 30) ÷ 3 = 20
The arithmetic mean shares the total equally
For n values, mean = sum of values ÷ n. The mean preserves the total: n multiplied by the mean equals the original sum, apart from display rounding.
How it works
Enter a comma-separated numeric list, review the count, and decide whether equal weighting and sensitivity to outliers fit the question.
Key concepts
Every entry has equal influence
Repeating a value gives it additional weight because it appears more times.
Mean and median answer different questions
The median depends on order and is usually less sensitive to extreme values.
When to use it
- Summarize equally weighted observations.
- Check a manual arithmetic mean.
- Find the balance point of a numeric list.
When not to use it
- Do not average percentages with different denominators naively.
- Do not hide strong skew or outliers.
- Do not use an unweighted mean when observations have different importance.
Worked examples
Balanced list
- Input
10, 20, 30- Expected output
20
The sum sixty is shared across three entries.
Outlier effect
- Input
10, 10, 100- Expected output
40
Most observations are ten, but the mean is raised by one extreme.
Negative values
- Input
−5, 0, 5- Expected output
0
Positive and negative totals cancel.
Common mistakes
Dividing by the wrong count
Blank or omitted entries change n. Correction: Review the parsed list.
Averaging averages without weights
Groups may have different sizes. Correction: Use group counts as weights or combine raw totals.
Calling mean typical automatically
Skew can make it unrepresentative. Correction: Inspect distribution and median.
Best practices
- Review values and count.
- Keep adequate precision until final display.
- Compare mean with range, median, or distribution when relevant.
Related operations and differences
Weighted Average Calculator
Choose Weighted Average Calculator when you need to calculate an average using matching weights.; use Average Calculator specifically for average.
Fraction to Decimal
Choose Fraction to Decimal when you need to convert a numerator and denominator to decimal.; use Average Calculator specifically for average.
Percentage Difference Calculator
Choose Percentage Difference Calculator when you need to compare two values by their average magnitude.; use Average Calculator specifically for average.
Proportion Calculator
Choose Proportion Calculator when you need to solve A:B = C:X safely.; use Average Calculator specifically for average.
Ratio Calculator
Choose Ratio Calculator when you need to calculate the ratio between two numbers.; use Average Calculator specifically for average.
Percentage Calculator
Choose Percentage Calculator when you need to calculate a percentage of any number.; use Average Calculator specifically for average.
Limitations and privacy
- Only the arithmetic mean is calculated.
- All entries receive equal weight.
- Invalid list values are rejected rather than inferred.
Numbers and results remain in this browser.
Frequently asked questions
What is arithmetic mean formula?
Sum of values ÷ number of values.
Do duplicates count more than once?
Yes. Every list position contributes equally.
Is mean the same as median?
No. Median is the middle ordered value.
Can I average group averages?
Only directly when groups have equal size; otherwise use weights.