⭕ Calculators

Circle Area Calculator

Calculate the area of a circle from its radius. Formula: A = π × r². Instant result in the browser.

Radius (r)

m²

Formula

A = π × r² ≈ 3.14159 × r²

where r is the circle radius. The area unit is the square of the radius unit (m², cm², km², etc.).

Convert Arabic numbers to Roman numerals and vice versa. Supports values from 1 to 3999. Instant bidirectional conversion.

Calculate the Greatest Common Divisor (GCD) of two or more numbers using the Euclidean algorithm. Instant result.

Calculate the Least Common Multiple (LCM) of two or more numbers. Instant result in the browser.