Standard Deviation Calculator

TQtech

Contains adsIn-app purchases

About this app

Standard Deviation Calculator — paste a dataset and get sample or population standard deviation in seconds, with every step shown.

This standard deviation calculator finds sample SD (s, n − 1) and population SD (σ, N). Switch formulas on the same list. See mean, variance, deviations, and the square root — not only the headline number.

HOW TO USE
• Paste or type numbers separated by commas, spaces, or new lines
• Choose Sample or Population
• Tap Calculate
• Open Show solution for the working table

WHAT YOU GET
• Sample standard deviation and population standard deviation
• Mean, variance, count, range, sum, min, max
• Median, Q1, Q3, IQR, coefficient of variation, standard error
• Step-by-step standard deviation: mean → deviations → squares → divide → square root
• Bell curve with the 68–95–99.7 rule, dataset bars, and a box plot
• Tap a value to see its z-score vs the mean
• History of recent calculations on this device

Built for homework, exam scores, lab readings, and class spread. Datasets stay on your phone — no account and no cloud sync of your numbers.

The calculator works offline. Ads, analytics, and purchases use the network when those features run.

LIFETIME PRO (optional, one-time — not a subscription)
Remove ads, keep 8 decimal places without a video, and export the working as PDF.

Standard Deviation Calculator by TQ Tech. Spread, instantly.

What’s new

Sample and population standard deviation with step-by-step working.