📉 Skewness Calculator
Measure the asymmetry of a dataset using adjusted sample skewness.
📊 Statistics📐 Formula included🧠 Practice questions✓ Free
Please enter valid values.
Formula and Explanation
Measure the asymmetry of a dataset using adjusted sample skewness.
| Concept | Formula or rule |
|---|---|
| Skewness Calculator | G₁ = n/[(n−1)(n−2)] × Σ[(xᵢ−x̄)/s]³ |
How to Use This Calculator
- Enter the sample, counts, probabilities, or summary statistics requested above.
- Keep paired lists in the same order and separate values with commas.
- Select the correct test direction or sample/population option when available.
- Press Calculate and interpret the result together with the supporting statistics.
Worked Example
Example: A long right tail usually produces positive skewness.
✓ Positive = right-skewed · Negative = left-skewed · Near 0 = roughly symmetric
Where This Is Used
School & coursework
Check homework, understand formulas, and verify step-by-step statistics exercises.
Research
Explore estimates, uncertainty, distributions, and relationships before using full statistical software.
Business & data analysis
Summarize variation, compare groups, and communicate data-driven findings clearly.
Common Mistakes to Avoid
⚠️
Equating zero skewness with normality
Many non-normal distributions are symmetric.
Many non-normal distributions are symmetric.
⚠️
Overinterpreting small samples
Sample skewness can fluctuate considerably.
Sample skewness can fluctuate considerably.
⚠️
Ignoring data errors
A single erroneous extreme value can dominate skewness.
A single erroneous extreme value can dominate skewness.
Practice Questions
1. Which direction is a long right tail?
Answer: Positive skew.
2. Which center is usually largest in strong right skew: mean or median?
Answer: Mean.
3. Does skewness measure spread?
Answer: No, it measures asymmetry.
Frequently Asked Questions
What is positive skew?▾
The distribution has a longer or heavier right tail.
What is negative skew?▾
The distribution has a longer or heavier left tail.
Is ±1 a strict cutoff?▾
No. Rules of thumb vary by field.