⭕ Calculators

Annulus Area Calculator

Calculate the area of a circular ring (annulus) from its outer and inner radii. Formula: A = π × (R² − r²).

Outer radius (R)

Inner radius (r)

m²

Formula

A = π × (R² − r²) where R > r.

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.