Math Tools
Calculate percentage change, averages and standard deviation; convert Roman numerals and number bases.
Roman Numeral Converter
Convert numbers to Roman numerals and back (2026 → MMXXVI); invalid numerals are flagged instantly.
Open toolRandom Number Generator
Generate one or thousands of random numbers in a range, with or without repeats, sorted or shuffled.
Open toolPercentage Change Calculator
Calculate the percentage increase or decrease between two values; e.g. 100 → 120 = 20% increase.
Open toolMean, Median and Mode Calculator
Paste a list of numbers and get count, sum, mean, median, mode, min, max and range instantly.
Open toolStandard Deviation Calculator
Find the sample or population standard deviation and variance of a list of numbers.
Open toolNumber Base Converter
Convert between binary, octal, decimal, hexadecimal and any base from 2 to 36; e.g. 255 = FF.
Open toolBitwise Calculator
Calculate AND, OR, XOR, NOT and shifts on 8, 16, 32 or 64-bit values with decimal, hex and binary output.
Open toolPrime Number Checker
Check whether a number is prime, see its prime factors and find the next and previous primes.
Open toolEveryday and academic calculations
Find a price increase, a salary raise or the sales change between two periods in seconds with the percentage change calculator. Get the mean, median, mode and standard deviation of a list of numbers without memorising formulas.
Number converters
Read or write Roman numerals, convert numbers between binary, hexadecimal and other bases, and find out whether a number is prime and what its prime factors are.
For programmers
The bitwise calculator shows AND, OR, XOR and shift results for 8, 16, 32 and 64 bit values.