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Count (n)
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Sum
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Min
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Max
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Mean (avg)
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Median
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Mode
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Range
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Std dev (pop.)
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Std dev (sample)
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Variance (pop.)
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Variance (sample)
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P25 (Q1)
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P50 (Q2 / Median)
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P75 (Q3)
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IQR (Q3 − Q1)
Statistics Calculator
Calculates descriptive statistics for a set of numbers: mean, median, mode, range, variance, standard deviation, quartiles, and more. Paste or enter a data set to get a complete summary.
Key statistics explained
| Statistic | Definition |
|---|---|
| Mean (average) | Sum of all values divided by count |
| Median | Middle value when sorted; solid to outliers |
| Mode | Most frequently occurring value |
| Range | Maximum minus minimum |
| Variance | Average squared deviation from the mean |
| Std. deviation | Square root of variance; same units as data |
| Q1 / Q3 | 25th and 75th percentile values |
| IQR | Q3 minus Q1; interquartile range |
When to use median vs. mean
Use the median when your data contains outliers, extreme values drag the mean away from the "typical" value. Income and house price data are classic examples where the median is more representative than the mean.
Standard deviation and normal distribution
In a normal distribution: ~68% of values fall within 1 std. deviation of the mean; ~95% within 2; ~99.7% within 3. This is the empirical rule (68-95-99.7 rule).