Find the Least Common Denominator for any number of fractions with full step-by-step working — including prime factorization, LCM method, and equivalent fractions with the LCD.
Up to 8 fractions · Prime factorization · GCD/LCM · Equivalent fractions · Fraction addition result
Enter Fractions
Enter the numerator and denominator for each fraction
Quick Examples
LCD Result
LEAST COMMON DENOMINATOR
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Equivalent Fractions with LCD
Step-by-Step Solution
Prime Factorization
Fraction Addition Result
Quick Result
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LCD
Denominators—
LCM method—
GCD (all denoms)—
Fraction count—
LCD vs LCM
LCD = Least Common Denominator — the LCM of the denominators of two or more fractions.
LCM = Least Common Multiple — the smallest positive integer divisible by all given numbers.
LCD = LCM(denominators) — they're identical for the purpose of adding fractions.
Adding Fractions
1. Find the LCD of all denominators
2. Convert each fraction to an equivalent fraction with the LCD
3. Add the numerators, keep the LCD as denominator
4. Simplify the result by dividing numerator and denominator by their GCD
Prime Factor Method
Factor each denominator into primes, then take the highest power of each prime that appears.