Find the LCD of the two denominators
Use the least common denominator so both fractions count the same-sized parts.
textLCD(4,3)=12Comparison fundamentals
Learn how to compare fractions and mixed numbers using four methods: common denominators, cross multiplication, decimal conversion, and whole-number-first. Includes a free instant comparison tool and 12 worked examples.
Written by
Mixed Number Lab Editorial Team
Focus
Which fraction is bigger?
Updated
2026-05-11
Core rule: Convert to the same denominator, then compare numerators
Find which fraction is greater, smaller, or equal
Left value
3/4
Right value
2/3
LCD = 12 -> 9/12 > 8/12
Instant Comparator
Enter two fractions or mixed numbers to see which is greater, with full step-by-step reasoning.
Instant Comparator
Enter two fractions or mixed numbers to compare values with a cross-check and full step-by-step reasoning.
Left value
Enter a whole part and a fraction.
Use +/- or drag a field sideways to adjust quickly.
Right value
Enter a whole part and a fraction.
Use +/- or drag a field sideways to adjust quickly.
Quick Refresher
Comparing fractions means deciding which of two fractions represents a larger or smaller amount, or whether they are equal. The challenge is that fractions use different denominators, which makes direct comparison impossible without a common reference point.
3/4 and 2/3 look close, but which is bigger? Converting both to twelfths, 9/12 and 8/12, makes the answer obvious.
Smaller
Fewer twelfths.
Result
The comparison symbol.
Larger
More twelfths.
Why Compare
Fraction comparison appears in ordering, simplification checks, recipes, and the classic which is greater test question.
Ordering fractions
OrderingSorting a list from least to greatest requires pairwise comparison.
Order fractions
Simplifying first
PrepAlways simplify before comparing to avoid unnecessary large numbers.
Simplify first
Recipe scaling
Real lifeDeciding whether 2/3 cup or 3/4 cup is more requires a direct comparison.
See cooking examples
Test problems
PracticeWhich is greater? is one of the most common fraction question types.
Use the calculator
Method 1
The common denominator method is the most reliable approach and the one taught in most classrooms. Once both fractions use the same denominator, the numerators tell you everything.
Use the least common denominator so both fractions count the same-sized parts.
textLCD(4,3)=12Rewrite each fraction as an equivalent fraction with denominator 12.
frac34=frac912,quad frac23=frac812Once denominators match, the larger numerator means the larger fraction.
9 > 8Return to the original values when writing the final comparison.
frac34 > frac23Common Reference
frac34=frac912>frac812=frac23Example 1
Twelfths make the comparison obvious.
Answer: 3/4 > 2/3
Example 2
Convert halves to eighths.
Answer: 1/2 > 3/8
Example 3
Both fractions convert cleanly to eighteenths.
Answer: 5/6 > 7/9
Example 4
Equivalent fractions land on the same numerator after conversion.
Answer: 2/5 = 4/10
Method 2
Cross multiplication gives the same result as the common denominator method but skips the LCD step. Multiply the numerator of each fraction by the denominator of the other, then compare the two products.
This creates the left cross product.
3 times 3 = 9This creates the right cross product.
2 times 4 = 8The products correspond to the original fractions.
9 > 8 Rightarrow frac34 > frac23Cross Multiplication Rule
a/b vs c/d
Compare: a x d vs b x c
If a x d > b x c, then a/b > c/d.
If a x d < b x c, then a/b < c/d.
If a x d = b x c, then a/b = c/d.
Cross Example 1
The left cross product is larger.
Answer: 3/4 > 2/3
Cross Example 2
The products differ by one.
Answer: 5/8 > 3/5
Cross Example 3
Equal cross products mean equal fractions.
Answer: 4/7 = 8/14
Method 3
Converting to decimals is the most intuitive method for many students because decimal comparison is straightforward. Divide each numerator by its denominator, then compare the decimal values.
Divide each numerator by its denominator.
frac34=3div4=0.75,quad frac23=2div3=0.overline6Decimal comparison is direct once both values use decimal notation.
0.75 > 0.666ldotsUse the original fractions in the final answer.
frac34 > frac23Mixed Number Example
Compare 2 3/4 and 2 2/3. 2 3/4 = 2.75, while 2 2/3 = 2.666... Result: 2 3/4 > 2 2/3.
Decimal Example 1
A terminating decimal and a repeating decimal are easy to compare.
Answer: 3/4 > 2/3
Decimal Example 2
Decimals make mixed-number comparison direct.
Answer: 1 1/2 < 1 3/5
Decimal Example 3
Improper fractions compare clearly after division.
Answer: 5/4 > 6/5
Method 4
When comparing mixed numbers, you can often skip full conversion. If the whole number parts are different, the larger whole number wins immediately. Only compare the fraction parts when the whole numbers are equal.
If the whole numbers are different, the larger whole number wins immediately.
3frac14 > 2frac78quad textbecause 3>2Use common denominators or cross multiplication on the fraction parts only.
2frac34text vs 2frac23Rightarrow frac34>frac23Rightarrow 2frac34>2frac23Decision Tree
Are the whole numbers different?
YES -> Larger whole number = larger mixed number.
NO -> Compare fraction parts using Method 1 or 2.
If fractions match, the mixed numbers are equal.
Whole First Example 1
Different whole numbers decide the comparison immediately.
Answer: 3 1/4 > 2 7/8
Whole First Example 2
Equal whole numbers mean the fraction parts decide.
Answer: 2 3/4 > 2 2/3
Whole First Example 3
Both the whole and fraction parts match.
Answer: 1 5/6 = 1 5/6
Use common denominators as the default, then choose shortcuts when the numbers make them useful.
| Compare | Method 1: Common Denominator | Method 2: Cross Multiply | Method 3: Decimal | Method 4: Whole First |
|---|---|---|---|---|
| Speed | Medium | Fast | Fast | Fastest (when applicable) |
| Best for | All fractions | Proper fractions | Mixed numbers | Mixed numbers with different wholes |
| Skill needed | Finding LCD | Multiplication | Division | Whole number comparison |
| Works with negatives | Yes | Caution | Yes | Yes |
| Recommendation | Best default | Quick shortcut | Most intuitive | Mixed numbers only |
Special Cases
These cases require a little more care because the most obvious visual comparison can be misleading.
Different-looking fractions can represent the same amount.
2/4 vs 1/2
Answer: 2/4 = 1/2
The value closer to zero is greater.
-1/2 vs -3/4
Answer: -1/2 > -3/4
With negative fractions, the rules flip. The fraction closer to zero is the greater value. Converting to decimals is often the clearest approach for negative comparisons.
A zero numerator makes the fraction equal to zero.
0/5 vs 1/8
Answer: 0/5 < 1/8
Put both values in a comparable format first.
7/4 vs 1 3/4
Answer: 7/4 = 1 3/4
Built-in Calculator
Enter two fractions or mixed numbers below to see which is greater, with the full step-by-step comparison.
Instant Comparator
Enter two fractions or mixed numbers to see which is greater, with full step-by-step reasoning.
Instant Comparator
Enter two fractions or mixed numbers to compare values with a cross-check and full step-by-step reasoning.
Left value
Enter a whole part and a fraction.
Use +/- or drag a field sideways to adjust quickly.
Right value
Enter a whole part and a fraction.
Use +/- or drag a field sideways to adjust quickly.
FAQ
Convert them to a common denominator, compare the numerators, and then write the correct comparison symbol between the original fractions.
For positive fractions, cross multiplication is usually fastest. For a classroom default, common denominators are the most reliable.
Compare the whole-number parts first. If they are equal, compare the fraction parts with common denominators, cross multiplication, or decimals.
Continue Learning
Simplify Fractions
Reduce fractions before comparing so the numbers stay manageable.
Ordering Fractions and Mixed Numbers
Extend pairwise comparison into sorting from least to greatest.
Mixed Number to Decimal
Use decimal conversion as an intuitive comparison method.
Fraction to Decimal
Practice the decimal method for proper and improper fractions.
Mixed Number Calculator
Return to the main tool for mixed-number operations and conversions.