Simplify Fractions Calculator
This simplify fractions calculator reduces any fraction to its lowest terms in one step. Type the top and bottom and you'll get the simplest form, the greatest common factor it divided by, the mixed number, and the decimal. It works on improper fractions too, and it shows the working, so you'll see exactly how the fraction was reduced.
- Lowest terms
- Shows the GCF
- Mixed number and decimal
- Handles improper
- Steps shown
Last updated June 16, 2026 Divide top and bottom by the GCF Reviewed by the Calcowa math team
Enter your fraction
Works on proper and improper fractions. The mixed number and decimal are shown too.
Enter a top and a bottom, with a bottom that isn't zero.
GCF(8, 12) = 4 → 8÷4 / 12÷4 = 2/3
How to simplify a fraction
Simplifying a fraction means writing it with the smallest whole numbers that still mean the same thing. The trick is the greatest common factor, the biggest number that divides both the top and bottom. Divide each by that factor and the fraction shrinks to its lowest terms while keeping the same value, so you're not changing the amount, just the look. So 8/12 and 2/3 are the same amount, just written differently, and that's all simplifying does.
Simplifying 8/12
Here's how the calculator reduces 8/12 to its lowest terms:
- 1
Find the GCFThe largest number that divides both 8 and 12 is 4.
- 2
Divide both8 ÷ 4 = 2 and 12 ÷ 4 = 3.
- 3
Read the resultThe simplest form is 2/3, which can't be reduced any further.
No GCF handy? You can also divide by any common factor and repeat, like halving 8/12 to 4/6 and again to 2/3. You'll land in the same place. To find that factor on its own, the GCF and LCM calculator shows the prime factors behind it.
Improper fractions and lowest terms
An improper fraction, where the top is bigger than the bottom, simplifies exactly the same way. Divide by the greatest common factor first, then write it as a mixed number if you want. For 18/8, the common factor is 2, giving 9/4, and that's the mixed number 2 1/4. A fraction is in lowest terms once no whole number larger than 1 divides both parts, and it'll show the mixed number alongside the simplified fraction.
Why simplify at all?
A simplified fraction is easier to read, compare, and work with. It's quicker to picture 2/3 than 8/12, and answers are usually expected in lowest terms. Simplifying also makes adding and comparing fractions less fiddly, since smaller numbers don't fight you. If you've got fractions to combine first, the fraction calculator adds, subtracts, multiplies, and divides them, and it simplifies the answer for you.
Simplified fraction examples
| Fraction | Simplest form | GCF |
|---|---|---|
| 8/12 | 2/3 | 4 |
| 10/15 | 2/3 | 5 |
| 16/64 | 1/4 | 16 |
| 9/12 | 3/4 | 3 |
| 18/24 | 3/4 | 6 |
Frequently asked questions
How do you know a fraction is fully simplified?
When the only number that divides both the top and bottom is 1. At that point there's nothing left to cancel, so the fraction is in lowest terms. The calculator checks this for you and tells you the factor it used.
Find the greatest common factor of the top and bottom, then divide both by it. For 8/12, the greatest common factor is 4, so it becomes 8 ÷ 4 over 12 ÷ 4, which is 2/3. A fraction is fully simplified when the top and bottom share no factor other than 1.
It's the largest number that divides both the top and bottom evenly. For 8 and 12, the common factors are 1, 2, and 4, so the greatest is 4. Dividing both by that single number reduces the fraction in one step, which is what the calculator does.
Lowest terms means the same fraction written with the smallest possible whole numbers. You get there by dividing the top and bottom by their greatest common factor, so 16/64 reduces to 1/4. Once no number bigger than 1 divides both, you're at lowest terms.
Simplest form is just another name for lowest terms: the fraction reduced as far as it'll go. So the simplest form of 18/24 is 3/4. The calculator shows the simplest form, the factor it divided by, and the decimal, all at once, so you've got everything in one place.
Simplify it the same way, by dividing by the greatest common factor, then write it as a mixed number if you like. For 18/8, the common factor is 2, giving 9/4, which is the mixed number 2 1/4. The result above shows the mixed number too.
No. A fraction is already in simplest form when its top and bottom share no common factor, like 2/3 or 5/7. In that case there's nothing to reduce, and the calculator just confirms it's already as simple as it gets.
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