Ratio Calculator
Simplest ratio
2 : 3
Unit form: 2/3 : 1
Original terms: 4 : 6
Step-by-step solution
- 1
Write each term as a fraction
Every integer, decimal or fraction becomes an exact fraction — nothing is rounded.
- 2
Multiply by the LCM of the denominators
Multiply every term by 1, the least common multiple of all denominators, to turn the ratio into whole numbers.
- 4 · 1 = 4
- 6 · 1 = 6
- 3
Divide by the GCD
Divide every term by 2, the greatest common divisor of those whole numbers, to reduce the ratio as far as possible.
- 4 ÷ 2 = 2
- 6 ÷ 2 = 3
- 4
Result
The simplest form of the ratio is 2 : 3.
- 5
Unit form (n : 1)
Divide both terms by the second term to get the unit form 2/3 : 1 — the first quantity per one unit of the second.
- 6
Decimal comparison
Divide each term by the first term to compare the ratio in decimals.
- 4 ÷ 4 = 1
- 6 ÷ 4 ≈ 1.5
Understanding ratios
A ratio compares quantities by division. The ratio 4 : 6 says that for every 4 of one thing there are 6 of another — the same information as the fraction 4/6. A ratio does not change when every term is multiplied or divided by the same number, so 4 : 6, 2 : 3 and 8 : 12 all describe the same relationship.
To simplify a ratio, write every term as a fraction, multiply all terms by the LCM of the denominators to get whole numbers, then divide by their GCD. A proportion sets two ratios equal: a : b = c : d. Cross-multiplying gives a · d = b · c, a simple equation you can solve for any one missing term.
Sharing an amount in a ratio means splitting it into parts proportional to the terms. Add the terms to get the total number of parts, then each share is amount × term ÷ total. Dividing 120 in the ratio 2 : 3 gives 48 and 72, and the shares always add back up to the original amount.