Mean, Median, Mode Calculator
Find mean, median, mode, range, variance, and standard deviation instantly — with step-by-step solutions, frequency chart, outlier detection, and skewness indicator.
How to Find Mean, Median, and Mode
Mean, median, and mode are the three measures of central tendency in statistics. They describe where the center of a dataset lies, each from a different perspective.
Mean Formula (Average)
Example: {2,4,6,8,10} → Mean = 30 ÷ 5 = 6
Median Formula (Middle Value)
Even count: Median = average of two middle values
Example: {1,3,5,7,9} → Median = 5
Mode Formula (Most Frequent)
Example: {2,3,3,4,5,5,5} → Mode = 5 (appears 3 times)
When to Use Mean vs Median vs Mode
- Use Mean: Symmetric data without outliers — test scores, heights, temperatures
- Use Median: Skewed data or when outliers exist — house prices, salaries, income
- Use Mode: Categorical data, shoe sizes, most popular item, most common response
What is Standard Deviation?
Standard deviation (σ) measures how spread out values are from the mean. A low σ means data is tightly clustered; a high σ means widely spread. Formula: σ = √(Σ(x-mean)² / n).
What are Outliers?
Outliers are values that lie far from the rest of the data. This calculator uses the IQR method: values below Q1−1.5×IQR or above Q3+1.5×IQR are flagged as outliers (shown in red).
Mean, Median, Mode — Real World Examples
- Test scores {70,80,85,90,95}: Mean=84, Median=85 — symmetric data, both similar
- Salaries {20k,22k,25k,28k,200k}: Mean=59k, Median=25k — outlier pulls mean up, use median
- Shoe sizes {7,8,8,9,9,9,10}: Mode=9 — most useful for inventory decisions
- Temperature {10,12,11,13,12,12}: Mode=12°C — most common temperature of the week
What is Skewness?
Skewness describes the asymmetry of a distribution:
- Symmetric: Mean ≈ Median — data is balanced (e.g. heights in a population)
- Positive Skew: Mean > Median — long tail on the right, high outliers exist (e.g. income data)
- Negative Skew: Mean < Median — long tail on the left, low outliers exist (e.g. exam scores when most do well)
Population vs Sample Standard Deviation
This calculator uses population standard deviation (σ) — divide by n. If your data is a sample from a larger population, use sample standard deviation (s) — divide by n−1. For most homework and school problems, population std dev is correct.
How to Find Mean Median Mode — Quick Reference
Range = Max − Min | Variance = Σ(x−mean)² / n | Std Dev = √Variance
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Frequently Asked Questions
CalcVelo Mean, Median, Mode Calculator — Free online statistics tool. Find mean, median, mode, range, variance, standard deviation with step-by-step solutions, frequency chart, outlier detection, and skewness indicator.