Standard Deviation Calculator
Enter a list of numbers to calculate standard deviation. Choose sample or population mode and see mean, variance, count, min, and max.
Separate values with commas, spaces, or new lines. Example: 10, 12 15 20
| Metric | Value |
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Privacy: calculations run locally in your browser. No values are stored or transmitted.
How it works
Population SD: σ = √(Σ(x−μ)² / N)
Sample SD: s = √(Σ(x−x̄)² / (N−1))
Examples
- Population example: 2, 4, 4, 4, 5, 5, 7, 9 → SD = 2
- Switch to sample mode when your values are a subset of a larger population
When to use this tool
This tool is designed for quick, practical tasks such as everyday calculations, data formatting, or simple conversions. It is best used when you need fast results without installing software or using complex tools.
When to use
- Quick checks or one-time calculations
- Validating or converting data before using it elsewhere
- Simple tasks that do not require advanced software
When not to use
- Critical financial, legal, or medical decisions
- Large-scale or automated processing
- Situations requiring guaranteed precision beyond basic validation
Always review results before using them in important contexts.
About this tool
This tool helps you perform quick utility operations directly in your browser. It runs entirely in your browser without sending data to a server.
You can use this tool when handling simple tasks without installing additional software. The results should be interpreted as a processed output based on your input data.
FAQ
- What is standard deviation?
Standard deviation measures how spread out values are around the mean. A larger value means more variation.
- What is the difference between sample and population standard deviation?
Population standard deviation divides by N. Sample standard deviation divides by N−1 to estimate spread from sample data.
- What separators can I use?
You can separate numbers with commas, spaces, tabs, or new lines.
- Are my numbers stored?
No. All calculations run locally in your browser and are not sent to a server.