Simplify Fractions Calculator

To simplify a fraction, divide both the numerator and denominator by their Greatest Common Divisor (GCD). For instance, 18/24 simplifies to 3/4 by dividing both parts by 6.
Enter Fraction to Reduce
Enter the numerator integer
Enter the non-zero denominator
Try an example:
Rounding rule: standard arithmetic half-away-from-zero (e.g., 2.55 rounded to 1 decimal is 2.6).
Simplest Form:
3/4
Greatest Common Divisor (GCD): 6 | Mixed: 3/4 | Decimal: 0.75
Fraction Model: 3 / 4
Step 1: Input fraction: 18/24.
Step 2: Find the Greatest Common Divisor (GCD) of 18 and 24: GCD = 6.
Step 3: Divide both numerator and denominator by 6: (18 ÷ 6) / (24 ÷ 6) = 3/4.
Step 4: Simplified fraction: 3/4.
Step 5: Decimal representation: 0.75.

How to Reduce Fractions to Lowest Terms

A fraction is in its simplest form (also known as lowest terms or reduced form) when its numerator and denominator are coprime integers, meaning they share no positive common divisors other than 1.

To simplify any proper or improper fraction, determine the Greatest Common Divisor (GCD) of the numerator and denominator using the Euclidean algorithm or prime factorization. Next, divide both the numerator and the denominator by this common factor. The resulting fraction represents the exact same numerical quantity with the smallest possible whole numbers.

If the numerator is greater than the denominator (an improper fraction), it can also be converted into a mixed number by dividing the numerator by the denominator to extract the whole integer and fractional remainder.

Our calculator provides the reduced fraction, the exact greatest common divisor, the mixed number representation, and the full decimal equivalent.

\frac{\text{Numerator}}{\text{Denominator}} = \frac{\text{Numerator} \div \gcd}{\text{Denominator} \div \gcd}

Worked Engineering Fraction Example

Worked Example: Reducing an Engineering Tolerance Fraction

In precision machining, a mechanical bracket is measured at 42/56 inches. Reduce this fraction to its lowest terms and express it as a decimal.

  1. Identify the numerator = 42 and denominator = 56.
  2. Find prime factors of both numbers: 42 = 2 × 3 × 7; 56 = 2 × 2 × 2 × 7.
  3. Determine the common prime factors: 2 × 7 = 14. Therefore, GCD(42, 56) = 14.
  4. Divide both terms by 14: (42 ÷ 14) / (56 ÷ 14) = 3/4.
  5. Convert 3/4 to decimal: 3 ÷ 4 = 0.7500 inches.

42/56 inches simplifies directly to 3/4 inches (0.7500 in decimal).

Fraction Simplification Reference Table

Use this reference table to inspect common unsimplified fractions, their Greatest Common Divisors, and reduced simplest equivalents.

Original FractionGreatest Common Divisor (GCD)Simplified FractionMixed NumberDecimal
4 / 841 / 21 / 20.5000
6 / 932 / 32 / 30.6667...
10 / 2552 / 52 / 50.4000
18 / 2463 / 43 / 40.7500
26 / 8213 / 43 1 / 43.2500
36 / 1212333.0000
45 / 60153 / 43 / 40.7500
125 / 10001251 / 81 / 80.1250

Common Fraction Simplification Pitfalls

Simplification Traps
  • Stopping after dividing by only one common factor: For example, dividing 36/48 by 2 gives 18/24, which can still be reduced further. Continue until the GCD is 1.
  • Dividing only the numerator or only the denominator: You must divide BOTH terms by the exact same divisor to preserve fraction equivalence.
  • Attempting to simplify fractions with a zero denominator: A denominator of zero is undefined in mathematics.
  • Dropping the negative sign: −18/24 simplifies to −3/4, retaining the negative sign in the numerator.

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Frequently Asked Questions About Simplifying Fractions

What is the fastest way to simplify fractions?

The fastest method is finding the Greatest Common Divisor (GCD) using the Euclidean algorithm and dividing both the top and bottom by that number in a single step.

Can all fractions be simplified?

No. Fractions whose numerator and denominator are already coprime (such as 3/7, 5/11, or 8/9) share no common divisor greater than 1 and are already in lowest terms.

What is 18/24 simplified?

18/24 simplifies to 3/4. Both 18 and 24 are divisible by their greatest common factor of 6.

What is an improper fraction in simplest form?

An improper fraction has a numerator larger than its denominator (like 13/4). In simplest form, the numbers share no common factors and can be expressed as a mixed number (3 1/4).

How do you simplify a fraction with large numbers?

Use successive Euclidean division: divide the larger number by the smaller, take the remainder, and repeat until the remainder is zero. The last non-zero divisor is the GCD.

Does simplifying a fraction change its value?

No. Simplifying changes the representation to smaller whole numbers while preserving the identical mathematical value and decimal equivalent.

Related Calculators

Want to master GCD algorithms and prime factor trees?Read our Complete Simplifying Fractions Guide →