圆面积计算器

Use the free online 圆面积计算器 tool. Fast, private and easy to use — runs entirely in your browser. Part of our 数学计算器 collection.

Radius

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

勾股定理计算器

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.

Is the 圆面积计算器 free to use?

Yes. The 圆面积计算器 is completely free with no sign-up, no limits and no watermarks. You can use it as many times as you like.

Is the 圆面积计算器 safe and private?

Absolutely. The 圆面积计算器 runs entirely in your browser, so your data never leaves your device and nothing is uploaded to a server.

Do I need to install anything to use the 圆面积计算器?

No installation is needed. The 圆面积计算器 works instantly online in any modern browser on desktop, tablet or mobile.

Does the 圆面积计算器 work on mobile phones?

Yes. The 圆面积计算器 is fully responsive and works smoothly on iPhone, Android and any other device.