Ratio Calculator

Simplify ratios to their smallest whole numbers, find a missing term in a proportion, and divide an amount in a given ratio — all computed exactly with fractions and shown step by step.
Computed
The exact result and the full working are shown below.
Resultexact

Simplest ratio

2 : 3

Unit form: 2/3 : 1

Original terms: 4 : 6

Step-by-step solution

  1. 1

    Write each term as a fraction

    Every integer, decimal or fraction becomes an exact fraction — nothing is rounded.

    4:64 : 6
  2. 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.

    (4:6)⋅1=4:6\left(4 : 6\right) \cdot 1 = 4 : 6
    • 4 · 1 = 4
    • 6 · 1 = 6
  3. 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.

    (4:6)÷2=2:3\left(4 : 6\right) \div 2 = 2 : 3
    • 4 ÷ 2 = 2
    • 6 ÷ 2 = 3
  4. 4

    Result

    The simplest form of the ratio is 2 : 3.

    4:6=2:34 : 6 = 2 : 3
  5. 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.

    23:1\frac{2}{3} : 1
  6. 6

    Decimal comparison

    Divide each term by the first term to compare the ratio in decimals.

    2:3=1:1.52 : 3 = 1 : 1.5
    • 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.