Simplify Calculator
Enter a numerator and a denominator to reduce the fraction to simplest form, with the GCF and each division shown. For example, 12/18 = 2/3 because both divide by 6. Improper fractions also come back as mixed numbers (10/4 = 2 1/2), and every answer includes its decimal.
Both 12 and 18 divide by 6, leaving 2/3 — the same value in the fewest possible pieces.
Find the greatest common factor
The GCF is the biggest whole number that divides both the numerator and the denominator.
GCF(12, 18) = 6Divide top and bottom by the GCF
Dividing both parts by the same number keeps the fraction's value identical — only the pieces change size.
1218÷ 6 on top and bottom
=23nothing bigger than 1 divides both now
12 ÷ 6 = 2 18 ÷ 6 = 3
Works instantly in your browser — nothing is uploaded, and the URL keeps your numbers so you can share the exact worked example.
Simplified fractions, worked
Common fractions reduced to lowest terms. Divide the numerator and denominator by the GCF to get the simplest form.
| Fraction | GCF | Simplest form | Mixed number | Decimal |
|---|---|---|---|---|
| 12/18 | 6 | 2/3 | — | ≈ 0.6667 |
| 6/8 | 2 | 3/4 | — | 0.75 |
| 8/12 | 4 | 2/3 | — | ≈ 0.6667 |
| 15/25 | 5 | 3/5 | — | 0.6 |
| 18/24 | 6 | 3/4 | — | 0.75 |
| 24/36 | 12 | 2/3 | — | ≈ 0.6667 |
| 45/60 | 15 | 3/4 | — | 0.75 |
| 42/56 | 14 | 3/4 | — | 0.75 |
| 10/4 | 2 | 5/2 | 2 1/2 | 2.5 |
| 27/6 | 3 | 9/2 | 4 1/2 | 4.5 |
| −12/18 | 6 | −2/3 | — | ≈ −0.6667 |
| 17/51 | 17 | 1/3 | — | ≈ 0.3333 |
Decimals are shown to 4 places; “≈” marks a rounded, repeating decimal.
One step or several?
You can cancel in stages — 12/18 ÷2 → 6/9 ÷3 → 2/3 — or in one move using the GCF: ÷6 straight to 2/3. Both are correct; the GCF route gets you to the finish line in a single division, which is why this calculator leads with it.