Math · 23 calculators
Math Calculators
From quick percentages to algebra and geometry, these tools solve the problem and show the result instantly — handy for homework, work, or everyday math.
Basic & percentages
Percentage Calculator
Find a percent, change, or "what percent of".
Percentage Change
Increase or decrease between two numbers.
Fraction Calculator
Add, subtract, multiply, and divide fractions.
Decimal to Fraction
Convert decimals into exact fractions.
Ratio Calculator
Simplify, scale, and solve ratios.
Average Calculator
Mean of any list of numbers.
Algebra
Scientific Calculator
Full scientific calculator in your browser.
Exponent Calculator
Raise numbers to any power.
Logarithm Calculator
Log of any number in any base.
Quadratic Formula
Solve ax² + bx + c = 0.
Root Calculator
Square, cube, and nth roots.
Percentage Error
Compare an estimate to the true value.
Geometry
Area Calculator
Area of common 2D shapes.
Volume Calculator
Volume of common 3D solids.
Circle Calculator
Radius, diameter, circumference, area.
Triangle Calculator
Sides, angles, area, and perimeter.
Pythagorean Theorem
Find a missing right-triangle side.
Perimeter Calculator
Perimeter of any standard shape.
Numbers & stats
About our math calculators
Math is faster when you can check your work. These calculators cover the everyday operations and the school-and-college essentials, each using the standard method so the answer matches what you would get by hand.
Every tool here is free, works instantly in your browser, and never stores the numbers you enter. They give reliable results for everyday use — treat anything high-stakes as a starting point and double-check with a professional.
Frequently asked questions
Yes. Every math calculator on OnlineCalculators.com is completely free, with no sign-up, account, or app required.