Loona Calculators
Enter two whole numbers — or three — and get their LCM (lowest common multiple) and HCF (highest common factor, also called GCD) at once. Essential for fractions, ratios and school maths.
The HCF is the largest number that divides both numbers exactly. The LCM is the smallest number that both numbers divide into exactly.
Yes — Highest Common Factor and Greatest Common Divisor are two names for the same value.
Adding and simplifying fractions needs the LCM of the denominators and the HCF of the numerator and denominator; ratio, tiling and scheduling problems use them too.