Variance and Standard Deviation Calculator

Quickly calculate data statistics such as variance, standard deviation, and mean, with support for single-set and batch calculations.

Bug report

Browser execution mode: Your data is processed in your browser and is not uploaded to the server.

Speed and Stability: Processing speed depends on your device and browser. For large batch work, the desktop version may be more stable.

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If the online tool fails to load or run, try the desktop tool.https://tools.yikeaigc.com/

Tool Usage

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Enter or import data, set calculation options, then generate results and export files.

Supports commas, spaces, line breaks, tabs, and “value:frequency” format. Batch files are read locally. The first 20 files are shown, and all selected files are processed.

Population/Sample Variance Standard Deviation & CV Quartiles & Outliers CSV / ZIP Export

Batch files

No files selected

After selecting multiple TXT or CSV files, the first 20 filenames appear here. ZIP downloads use original filenames; duplicates are numbered automatically.

Click to select batch data files You can also drag .txt / .csv files here.

1Enter Single Dataset

Paste Excel columns, CSV rows, or frequency distribution data.

Import TXT/CSV

2Calculation parameters

Use default settings first, then adjust for your analysis.

Decimal Precision

Variance Type

Outlier Method

Z Threshold

Mean Confidence Level

Result Display

Calculation Steps Charts Outlier Deduplicate Before Calculation Show Ascending

3Calculation results

Results are generated using the current parameters.

Frequency Distribution Histogram

Box Plot

1Enter Multiple Data Sets

Each line is one data set; you can also use the batch file upload above.

2Batch Parameters

Batch preview shows the first 50 sets; export includes all valid results.

Decimal Precision

Output Content

Variance Type

Result sorting

Deduplicate each group Ascending within group Export error rows

3Bulk Results

Results will be generated with current settings.

Formula reference

Population variance / SD σ² = Σ(xᵢ - μ)² / N，σ = √σ²

Sample variance / SD s² = Σ(xᵢ - x̄)² / (n - 1)，s = √s²

IQR and outliers IQR = Q3 - Q1；低界 = Q1 - 1.5 × IQR；高界 = Q3 + 1.5 × IQR

Coefficient of variation CV = 样本标准差 / |平均值| × 100%

Instructions

Software Usage Instructions

Select calculation mode: The tool provides two modes: single-set calculation and batch calculation. Single-set calculation is suitable for analyzing one set of data, while batch calculation is suitable for processing multiple sets of data by row or by file.
Enter or import data: You can paste numbers directly or import TXT or CSV files. English commas, spaces, line breaks, and tabs are supported as separators, and the value:frequency format is also supported, such as 10:3, 20:5.
Set calculation parameters: You can set decimal precision, variance type, outlier detection method, Z-score threshold, confidence level, whether to display charts, whether to show calculation steps, and whether to remove duplicates and sort.
Start calculation: In single-set mode, click “Next: Start Calculation”; in batch mode, click “Next: Batch Calculation”. You can also use Ctrl+Enter to run the calculation for the current mode.
View analysis results: Single-set mode displays the mean, variance, standard deviation, quartiles, IQR, coefficient of variation, skewness, kurtosis, confidence interval, outlier results, histogram, and box plot.
Process data in batches: In batch mode, each row is treated as one data set. When multiple TXT or CSV files are selected, the interface displays the first 20 files, while all files are calculated during processing.
Export results: Single-set results can be copied or downloaded as CSV; batch results can be copied, downloaded as CSV, or generated by original file name and packaged for ZIP download. Files with duplicate names will automatically be distinguished by adding numbers.
Save settings: Click “Save Settings” to save the current parameters, which will be restored automatically the next time you open the tool.

FAQ

A: Population variance is used to describe the dispersion of a complete data set, with N as the denominator. Sample variance is used to estimate the population dispersion from a sample, with n-1 as the denominator. If the data represents all objects, use population variance; if the data comes from sampling, sample variance is recommended.

A: Variance indicates how dispersed the data is around the mean, and standard deviation is the square root of variance. Standard deviation uses the same unit as the original data, making it easier to read for scores, experimental data, quality inspection, and risk analysis.

A: English commas, spaces, line breaks, and tabs are supported as separators. You can also copy data from a table and paste it directly. Frequency data can use the value:frequency format; for example, 15:4 means the value 15 appears 4 times.

A: The IQR method identifies outliers based on the interquartile range and is suitable for skewed data and data with extreme values. The Z-Score method identifies outliers based on the standard deviation distance between the data and the mean, and is suitable for data close to a normal distribution. The modified Z-Score uses the median and MAD, making it more robust against extreme values.

A: The coefficient of variation is the ratio of the sample standard deviation to the absolute value of the mean, usually displayed as a percentage. It is useful for comparing the dispersion of data with different units or different mean levels, such as products from different batches, grades from different classes, or data from different experimental groups.

A: Batch calculation supports downloading a CSV summary as well as a ZIP file. When multiple files are used, result files will try to keep the original file names. If duplicate names occur, a number will be automatically added to the file name to make them easy to distinguish.

A: Common reasons include fewer than 2 valid numbers in the row, unrecognized characters, an incorrect frequency format, or only one valid value remaining after deduplication is enabled. Check the delimiters, number format, and value:frequency syntax, then recalculate.