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Free Math Tools

Percentages, statistics, and number tools

Percentage Calculator

Calculate percentages, percentage change, and what percent one number is of another.

Random Number Generator

Generate random numbers in any range. Single number, list, or unique set — no repeats.

Standard Deviation Calculator

Paste a list of numbers and get mean, median, mode, variance, and standard deviation instantly.

Correlation Calculator

Enter two sets of numbers and calculate Pearson correlation coefficient with interpretation.

Sample Size Calculator

Calculate the required sample size for any survey or experiment. Set confidence level and margin of error.

Mean, Median & Mode Calculator

Enter a list of numbers and calculate mean, median, mode, range, and sum instantly.

Free Math Calculators & Tools

All tools on this page are completely free to use, require no account or signup, and run entirely in your browser. Your data is never sent to a server. Results are instant.

These tools are built for professionals who need quick, accurate answers — not long explanations. Every calculator shows its formula so you can verify the logic.