Trimmed Mean Calculator
A trimmed mean removes a chosen percentage from both ends of sorted data before calculating an average.
How to use this calculator
- Enter the observations and the percentage to trim from each end. The number retained and ordinary mean are displayed.
- Check the labels and units before using a result outside this page.
- Change one input at a time if you want to compare scenarios.
Formula and method
Trim floor(pn/100) observations from each tail, then average the remaining values.
- Trim floor(pn/100) observations from each tail, then average the remaining values.
- The percentage is applied to each tail and rounded down to a whole observation; results depend on sample size.
Worked examples
Worked example
For 10, 12, 13, 14 and 100 with a 10% trim, no values are removed because floor(5 × 0.10) = 0.
The retained values are 10, 12, 13, 14 and 100, giving an average of 29.8 for this small sample.
The retained values are 10, 12, 13, 14 and 100, giving an average of 29.8 for this small sample.
Understanding the result
A trimmed mean removes a chosen percentage from both ends of sorted data before calculating an average.
The percentage is applied to each tail and rounded down to a whole observation; results depend on sample size.
Important notes
The percentage is applied to each tail and rounded down to a whole observation; results depend on sample size.
Displayed outputs are rounded for readability; preserve full precision when continuing a calculation.
Frequently asked questions
What does this trimmed mean calculator show?
A trimmed mean removes a chosen percentage from both ends of sorted data before calculating an average.
Which inputs should I check first?
Enter the observations and the percentage to trim from each end. The number retained and ordinary mean are displayed.
Can the result be used as a final professional specification?
The percentage is applied to each tail and rounded down to a whole observation; results depend on sample size.
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- Mean Absolute Deviation Calculator — Measure the average absolute distance of data values from their arithmetic mean.
Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
- How to Calculate a Z-Score — Learn how a z-score shows how far a value is from the mean in standard-deviation units.
- How to Calculate Percentage Change — Learn the percentage change formula, how to calculate increases and decreases, and why the original value matters.
- Percentage — Understand what a percentage means, how percentages are calculated, and when to use a percentage calculator.
This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.