Math & Converter Calculators
13 free tools for percentage, unit conversion and numerical calculations.
Percentage Calculator
Percentage increase, decrease and ratio calculations
Calculate →Standard Deviation Calculator
Standard deviation and variance of a data set
Calculate →Calculator
Calculator for basic arithmetic operations
Calculate →Scientific Calculator
Trigonometry, logarithm and exponent calculations
Calculate →Mean, Median, Mode Calculator
Statistical central tendency measures
Calculate →Square Meter Calculator
Calculate room and area in square meters
Calculate →Weight Converter
Convert between kg, pounds, ounces, grams and tonnes
Calculate →Length Converter
Convert meters, miles, inches, feet, yards, km
Calculate →Dimensional Weight Calculator
Dimensional weight for shipping and cargo
Calculate →Roman Numeral Converter
Convert numbers to Roman numerals
Calculate →Random Number Generator
Generate random numbers for draws and games
Calculate →Password Combination Calculator
Password security strength and combination count
Calculate →Coin Flip
Digital coin toss simulator
Calculate →Practical Tools for Everyday Math
The percentage calculator is the most used tool in this category: it handles discounts, raises, VAT and rate-of-change scenarios on a single screen. On the statistics side, the mean-median-mode and standard deviation tools show a dataset's typical value and spread; the results screen tells you when a skewed distribution makes the median more trustworthy than the mean.
The unit converters (length, weight) work in both metric and imperial. If you ship packages, the dimensional weight tool computes volumetric weight; carriers bill whichever is larger between actual and dimensional weight, which is why bulky-but-light parcels produce surprise costs. The password combination calculator shows how many possible combinations a password contains and its estimated brute-force cracking time.
The scientific calculator supports trigonometry, logarithms and exponents; the random number generator and coin flip tools give instant in-browser results for draws and decisions.