Statistics & Number Calculators
Crunch data and convert numbers. Calculate mean, median, mode, standard deviation, z-scores, probability, and confidence intervals, and work with binary, number bases, hashes, and other developer tools.
20 free calculators · no sign-up · instant results
Statistics
Combination Calculator
Combinations C(n,r) and permutations P(n,r)
Z-Score Calculator
Standard score and percentile for normal distributions
Standard Deviation Calculator
Standard deviation, variance & mean (sample or population)
Mean, Median, Mode Calculator
Mean, median, mode, and range for any data set
Probability Calculator
Single and two-event probability with and/or/not
Confidence Interval Calculator
Confidence interval & margin of error for a mean
Sample Size Calculator
How many people to survey for a reliable result
Number Systems
Random Number Generator
Random numbers in any range
Binary Converter
Convert between binary, decimal, hex, and octal
Scientific Notation
Convert to and from scientific notation
Prime Number Calculator
Check if a number is prime or find the nth prime
Significant Figures Calculator
Count sig figs and round to any precision
Roman Numeral Converter
Convert numbers to/from Roman numerals
Number to Words Converter
Convert any number to English words
Number Base Converter
Convert between binary, decimal, hex, octal, and any base 2–36
Developer Tools
Password Generator
Strong random passwords with entropy score
Color Converter
Convert between HEX, RGB, and HSL color codes
Hash Calculator
Generate MD5, SHA-1, SHA-256 & SHA-512 hashes from text
Base64 Calculator
Encode text to Base64 or decode it back (UTF-8 safe)
URL Encode Calculator
Percent-encode text for URLs or decode it back
Frequently asked questions
Which calculator finds standard deviation?
The Standard Deviation Calculator computes both sample and population standard deviation, plus variance and the mean, from any list of numbers.
Can I convert between number systems?
Yes — use the Binary, Number Base, and Scientific Notation calculators to convert between decimal, binary, hexadecimal, and more.