Proportional Calculator

Tags: Math Tools, Calculator, Proportion, Ratio Calculator

Introduction

The online proportional calculator helps you calculate the fourth value in a proportion when you have any three values. A proportion is an equation stating that two ratios are equal. It is commonly expressed as a:b = c:d or a/b = c/d.

This tool is useful for solving various mathematical problems involving ratios and proportions, such as scaling recipes, calculating distances on maps, determining percentages, and solving various real-world problems.

How to Use

1. Enter any three values in the proportion calculator.
2. The calculator will automatically compute the fourth value to maintain the proportional relationship.
3. Input values can be any integer or decimal number.
4. Copy: Copy the calculation results with one click.
5. Reset: Clear all input values to start a new calculation.

Common Ratios

For your convenience, we provide a list of commonly used ratios that you can quickly apply:

• 3:2 - Classic film and photo aspect ratio
• 4:3 - Standard TV and computer screen aspect ratio
• 16:9 - Widescreen TV and computer monitor aspect ratio
• 2:1 - Common in architectural drawings
• 1.618:1 - Golden ratio, widely used in art and design
• 2.35:1 - Cinemascope movie aspect ratio
• 3:4 - Portrait orientation of 4:3
• 4:5 - Common photo print size ratio
• 9:16 - Vertical video aspect ratio for mobile devices
• 1:2 - Common in paper sizes (e.g., A4, A3)
• 5:3 - Used in some digital camera aspect ratios

To use these ratios, simply click on any of them to automatically fill values for 'a' and 'b', then enter your 'c' value to calculate 'd'.

Important Notes

1. Denominator cannot be zero. When calculating a denominator, the numerator cannot be zero either.
2. Make sure to enter valid numeric values in the input fields.
3. The calculator works with both integers and decimal numbers.

Applications

• Scaling recipes in cooking
• Calculating distances on maps
• Determining percentages
• Converting between different units
• Solving mathematical problems involving ratios
• Financial calculations
• Engineering and architectural scaling

Example

If you know that 2:3 = 4:x, you can enter 2, 3, and 4 into the calculator to find that x = 6.

Similarly, if you have the proportion 5/10 = x/20, you can enter 5, 10, and 20 to find that x = 10.