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Ratio Calculator – Simplify, Scale & Solve Proportions

Simplify ratios, solve proportions, and compare ratios

Calculate Ratio

How to Use

  1. Select the type of calculation you need
  2. Enter the required values
  3. Click calculate to see the result
  4. View the simplified ratio or solution

What is a Ratio?

A ratio is a comparison of two or more quantities. It shows how much of one thing there is compared to another. Ratios can be written in several ways: a:b, a to b, or a/b.

For example, if there are 3 apples and 5 oranges, the ratio of apples to oranges is 3:5.

Simplifying Ratios

To simplify a ratio, divide both parts by their greatest common divisor (GCD). A simplified ratio has no common factors other than 1.

Example: 12:18 → GCD is 6 → 12÷6 : 18÷6 = 2:3

Proportions

A proportion is an equation stating that two ratios are equal: a:b = c:d. This can also be written as a/b = c/d.

The cross-product property states: if a:b = c:d, then a×d = b×c. This is useful for solving for unknown values.

Real-World Applications

  • Cooking and recipes (scaling ingredients)
  • Maps and scale drawings
  • Financial calculations (exchange rates, interest)
  • Mixing solutions and chemicals
  • Photography (aspect ratios)
  • Construction and architecture

Frequently Asked Questions

What's the difference between a ratio and a fraction?
While ratios and fractions look similar, a ratio compares two separate quantities (like apples to oranges), while a fraction represents a part of a whole (like 3/8 of a pizza). Ratios can also compare more than two quantities.
How do I know if two ratios are equivalent?
Two ratios a:b and c:d are equivalent if their cross products are equal (a×d = b×c). You can also simplify both ratios to their lowest terms and check if they're the same.
Can ratios have decimals?
Yes, ratios can have decimal values. However, it's often cleaner to express them as whole numbers. Multiply both parts by a power of 10 to eliminate decimals, then simplify.
What is a golden ratio?
The golden ratio is approximately 1:1.618 (or φ ≈ 1.618). It appears frequently in nature, art, and architecture and is considered aesthetically pleasing.