Fraction Comparison Calculator
Compare two fractions and determine which is larger, smaller, or if they are equal.
Inputs
Comparison Result
3/4 > 5/7
Fraction A as Decimal
0.750000
Fraction B as Decimal
0.714286
Common Denominator
28
Step by step
Cross multiply to compare
3 × 7 = 21; 5 × 4 = 20
= Left is larger
Common denominator
LCD(4, 7) = 28
= 21/28 vs 20/28
Decimal equivalents
3/4 = 0.750000; 5/7 = 0.714286
How it works
Two fractions a/b and c/d can be compared exactly by cross-multiplication: if a×d > c×b then a/b is larger. This avoids floating-point errors entirely and works for any integers.
Formula
Cross-multiplication comparison
a/b compared to c/d: compare a×d with c×b
- a
- Numerator of first fraction
- b
- Denominator of first fraction
- c
- Numerator of second fraction
- d
- Denominator of second fraction
Frequently Asked Questions
Why use cross-multiplication instead of decimals?
Cross-multiplication compares fractions exactly using only integer arithmetic, avoiding any floating-point rounding errors that decimal conversion might introduce.
What if the fractions are equal?
Equal fractions cross-multiply to the same value. For example, 2/4 and 3/6 both give 2×6 = 12 and 3×4 = 12.