Ratio Calculator
Enter two numbers to reduce their ratio to its simplest form. Add a new first value to scale the ratio while keeping the same proportions.
Type a number and the answer appears straight away.
12 : 18 simplifies to2 : 3
- As 1 : n
- 1 : 1.5
- As n : 1
- 0.666667 : 1
- A as a share of the total
- 40%
- B as a share of the total
- 60%
- Same ratio starting from 10
- 10 : 15
The math behind it: Ratio
divide both numbers by their greatest common factor; to scale: B2 = A2 x B / A
The ratio 12 : 18 simplifies to 2 : 3, because both numbers divide by 6. Keeping the same ratio from a new first value of 10 gives 10 : 15. As a share of the total, 12 : 18 is a 40% to 60% split.
Common questions
How do I simplify a ratio?
Divide both numbers by their greatest common factor. For 12 : 18 that factor is 6, giving 2 : 3.
How do I calculate a ratio of two numbers?
Write the two numbers with a colon between them and simplify. If a class has 12 boys and 18 girls, the ratio of boys to girls is 12 : 18, which is 2 : 3.
How do I scale a ratio?
Multiply both sides by the same number. To keep 2 : 3 with a first value of 10, multiply both sides by 5 to get 10 : 15.
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