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Standard Deviation Calculator

Paste a list of numbers — get mean, median, mode, sample + population standard deviation, variance, min/max/range, Q1/Q3, IQR. Complete descriptive statistics in one tool.

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8 values parsed
Mean (average)
22.75
Standard deviation (sample)
7.363
Population: 6.8875
Central tendency
Count (n)8
Sum182
Mean22.75
Median23.5
Modeno mode
Spread / variability
Variance (sample, n−1)54.2143
Variance (population, n)47.4375
SD (sample, n−1)7.363
SD (population, n)6.8875
Min12
Max33
Range21
Q1 (25th percentile)15
Q3 (75th percentile)27
IQR12
Sample (n−1) vs Population (n): use sample SD when your data is a subset of a larger population (most cases — surveys, experiments, A/B tests). Use population SD only when you have measured every member of the group.
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Inside the tool

What powers the Standard Deviation Calculator

Mean, median, mode

Sample SD (n−1) and population SD (n)

Variance (both formulas)

Min, max, range

Q1, Q3, IQR

Handles comma / space / newline input

Built differently

Why the Standard Deviation Calculator is different

Browser-native

The Standard Deviation Calculator runs entirely in your browser. Input is processed locally — never uploaded, never logged, never cached anywhere outside your device.

No artificial limits

No daily quotas, no character ceilings, no "upgrade for more" walls. Every feature is the complete feature — the same on the first use as the thousandth.

Production-grade quality

Built to the same engineering bar as paid SaaS tools — accurate algorithms, audited logic, responsive design and accessibility-tested interactions.

Use Contexts

Common use contexts

  • Statistics homework
  • Data analysis quick-check
  • A/B test result review
  • Engineering quality control
Privacy by design

Private and secure

Zero upload

All processing happens in your browser. Input is never transmitted, logged or cached.

Works offline

Once the page loads, the tool runs without an internet connection. No network calls happen during use.

No tracking

No accounts, no cookies for tool state. Only aggregate analytics count visits at the page level.

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