เครื่องคิดเลขคณิตศาสตร์

Free online math calculators for geometry, algebra, fractions and percentages — instant answers right in your browser.

เครื่องคิดเลขพื้นที่วงกลม

Radius

Find the area, circumference and diameter of a circle from its radius using A = πr².

Side a Side b Hypotenuse c (leave blank to solve)

Solve any missing side of a right triangle with a² + b² = c². Enter two sides and get the third.

a b c

Solve ax² + bx + c = 0 with the quadratic formula, including the discriminant and complex roots.

Numerator Denominator

Reduce any fraction to lowest terms, see it as a mixed number and as a decimal.

First number Second number

Find the greatest common factor and least common multiple of two whole numbers instantly.

Original value New value

Work out the percentage increase or decrease between two values, plus the absolute difference.

x₁ y₁ x₂ y₂

Get the slope, line equation and distance between two points on a graph.

Radius or Diameter

Find the circumference and area of a circle from its radius or diameter with C = πd.

Base Exponent

Raise any number to any power, including negative and fractional exponents.

Number x Base

Compute the logarithm of any number in any base, with natural log and log base 10 included.

Calculate n! exactly for small numbers and in scientific notation up to 170!.

First value Second value

Simplify any ratio to lowest terms and see its 1 : n form — decimals supported.