Ratio Calculator

What is a Ratio Calculator?

A ratio calculator is a tool used to determine the missing value in a proportion where three out of four values are known. It's based on the principle that in a valid proportion, the ratio of the first two numbers equals the ratio of the second two numbers.

How to Calculate Using a Ratio Calculator

To use a ratio calculator:

• Input any three known values in the proportion A:B = C:D
• The calculator will automatically determine which value is missing
• It then applies the appropriate formula to calculate the missing value
• The result ensures that the equality of the ratios is maintained

Formula

The general formula for a ratio calculator is:

\[ \frac{A}{B} = \frac{C}{D} \]

Depending on which value is missing, we can rearrange this to solve for the unknown:

• If A is missing: \( A = \frac{B \times C}{D} \)
• If B is missing: \( B = \frac{A \times D}{C} \)
• If C is missing: \( C = \frac{A \times D}{B} \)
• If D is missing: \( D = \frac{B \times C}{A} \)

Calculation Steps

1. Identify the three known values in the proportion A:B = C:D
2. Determine which value is missing
3. Apply the appropriate formula based on which value is missing
4. Perform the calculation to find the missing value
5. Verify that the resulting proportion maintains the equality of ratios

Example

Let's calculate the missing value in the proportion 3:4 = 6:x

1. Known values: A = 3, B = 4, C = 6
2. Missing value: D = x
3. Apply the formula: \( D = \frac{B \times C}{A} = \frac{4 \times 6}{3} = 8 \)
4. The missing value is 8
5. Verify: 3:4 = 6:8 (both reduce to 3:4)

Visual representation of the proportion 3:4 = 6:8