Math and Units Utilities & Operator Guides
Percentages, ratios, unit conversion and everyday arithmetic calculators.
Quick Summary / Direct Answer
OpenTools has 68 working math and units tools. Each one runs in your own browser tab, so your files and inputs never touch a server. There is no account and no paywall.
Category Specifications
Working tools
68
Server upload
None
Runs on
Your browser
Cost
Free, no paywall
All Math and Units tools
Read the guide, or open the tool straight away.
Basic Calculator
Run basic calculator in your browser tab.
Scientific Calculator
Run scientific calculator in your browser tab.
Fraction Calculator
Run fraction calculator in your browser tab.
Percentage Calculator
Run percentage calculator in your browser tab.
Ratio Calculator
Run ratio calculator in your browser tab.
Proportion Calculator
Run proportion calculator in your browser tab.
Average Calculator
Run average calculator in your browser tab.
Median Calculator
Run median calculator in your browser tab.
Mode Calculator
Run mode calculator in your browser tab.
Standard Deviation Calculator
Run standard deviation calculator in your browser tab.
Variance Calculator
Run variance calculator in your browser tab.
Probability Calculator
Run probability calculator in your browser tab.
Permutation Calculator
Run permutation calculator in your browser tab.
Combination Calculator
Run combination calculator in your browser tab.
Prime Number Checker
Run prime number checker in your browser tab.
Prime Factorization
Run prime factorization in your browser tab.
GCD Calculator
Run gcd calculator in your browser tab.
LCM Calculator
Run lcm calculator in your browser tab.
Quadratic Equation Solver
Run quadratic equation solver in your browser tab.
Linear Equation Solver
Run linear equation solver in your browser tab.
System of Equations Solver
Run system of equations solver in your browser tab.
Matrix Calculator
Run matrix calculator in your browser tab.
Determinant Calculator
Run determinant calculator in your browser tab.
Complex Number Calculator
Run complex number calculator in your browser tab.
Logarithm Calculator
Run logarithm calculator in your browser tab.
Exponent Calculator
Run exponent calculator in your browser tab.
Root Calculator
Run root calculator in your browser tab.
Geometry Calculator
Run geometry calculator in your browser tab.
Triangle Calculator
Run triangle calculator in your browser tab.
Circle Calculator
Run circle calculator in your browser tab.
Rectangle Calculator
Run rectangle calculator in your browser tab.
Polygon Calculator
Run polygon calculator in your browser tab.
Volume Calculator
Run volume calculator in your browser tab.
Surface Area Calculator
Run surface area calculator in your browser tab.
Distance Converter
Run distance converter in your browser tab.
Area Converter
Run area converter in your browser tab.
Volume Converter
Run volume converter in your browser tab.
Mass Converter
Run mass converter in your browser tab.
Temperature Converter
Run temperature converter in your browser tab.
Speed Converter
Run speed converter in your browser tab.
Time Unit Converter
Run time unit converter in your browser tab.
Pressure Converter
Run pressure converter in your browser tab.
Energy Converter
Run energy converter in your browser tab.
Power Converter
Run power converter in your browser tab.
Force Converter
Run force converter in your browser tab.
Torque Converter
Run torque converter in your browser tab.
Angle Converter
Run angle converter in your browser tab.
Frequency Converter
Run frequency converter in your browser tab.
Data Size Converter
Run data size converter in your browser tab.
Fuel Economy Converter
Run fuel economy converter in your browser tab.
Cooking Unit Converter
Run cooking unit converter in your browser tab.
Roman Numeral Converter
Run roman numeral converter in your browser tab.
Number to Words
Run number to words in your browser tab.
Words to Number
Run words to number in your browser tab.
Significant Figures Calculator
Run significant figures calculator in your browser tab.
Scientific Notation Converter
Run scientific notation converter in your browser tab.
Rounding Calculator
Run rounding calculator in your browser tab.
Margin of Error Calculator
Run margin of error calculator in your browser tab.
Confidence Interval Calculator
Run confidence interval calculator in your browser tab.
Z Score Calculator
Run z score calculator in your browser tab.
Percentile Calculator
Run percentile calculator in your browser tab.
Correlation Calculator
Run correlation calculator in your browser tab.
Linear Regression Calculator
Run linear regression calculator in your browser tab.
Sample Size Calculator
Run sample size calculator in your browser tab.
Random Number Generator
Run random number generator in your browser tab.
Dice Roller
Run dice roller in your browser tab.
Coin Flipper
Run coin flipper in your browser tab.
Sequence Generator
Run sequence generator in your browser tab.