Ratio Calculator
Enter a ratio to reduce it to its lowest terms.
A ratio calculator with two modes. Reduce any ratio like 18:24 to its lowest terms (3:4) using the greatest common divisor, or solve a proportion such as 2:3 = 10:x to find the unknown value. Type the numbers and the answer updates instantly, with zero denominators handled safely.
How to use
- Pick a mode: simplify a ratio, or solve a proportion.
- To simplify, enter both whole number terms (for example 18 and 24).
- To solve a proportion, enter a, b, and c for a:b = c:x.
- Read the result instantly in the output area below.
- Use Copy result to grab the answer, or Reset to clear the fields.
Examples
- Simplify 18:24, the calculator divides both terms by 6 to give 3:4.
- Solve 2:3 = 10:x, the answer is x = 15.
- Solve 4:5 = 3:x, the answer is x = 3.75.
FAQs
- How do you simplify a ratio?
- Divide both terms by their greatest common divisor (GCD). For 18:24 the GCD is 6, so the ratio reduces to 3:4. This calculator does that step automatically.
- What is a proportion?
- A proportion states that two ratios are equal, written a:b = c:x. Given any three values, you can solve for the fourth. Here x is found with x = (b times c) divided by a.
- Why can the first term of a proportion not be zero?
- Solving a:b = c:x divides by a, so a value of zero would mean dividing by zero, which has no answer. The calculator flags this instead of returning an error value.
- Can I simplify a ratio with decimals?
- Simplify mode works on whole numbers, since a ratio of counts is reduced using the GCD. If you have decimals, scale both terms to whole numbers first (for example 1.5:2 becomes 3:4).
- Does it handle negative numbers?
- Yes. In simplify mode a negative ratio is reduced and the sign is kept on the first term, so 6:-9 becomes -2:3.
- Are my numbers sent anywhere?
- No. All calculations run in your browser. Nothing you type is uploaded or stored.
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