Proportion Calculator
Solve proportion problems using cross-multiplication. Enter three values to find the fourth. Perfect for students, teachers, and professionals working with ratios and proportions.
Proportion Calculator
Solve proportion problems using cross-multiplication. Enter three values to find the fourth.
Enter Your Proportion
About Proportions
• Proportions show equality between two ratios
• Cross-multiplication: a/b = c/d → a×d = b×c
• Leave one value empty to solve for it
• Valid proportions have equal cross-products
Common Proportion Examples
Understanding Proportions
A proportion is a statement that two ratios are equal. It shows the relationship between four quantities where the ratio of the first two equals the ratio of the last two.
Proportions are fundamental in mathematics and have wide applications in science, engineering, cooking, art, and everyday problem-solving. They help us scale objects, mix ingredients, and solve many real-world problems.
Our calculator uses the cross-multiplication method to solve proportions. When you have a proportion like a:b = c:d, the cross-products are equal: a×d = b×c. This allows us to find any missing value.
How to Use This Calculator
Tips for Working with Proportions
Cross-Multiplication
Remember that a:b = c:d means a×d = b×c. This is the key to solving proportions.
Verification
Always check that your solution makes the proportion valid by testing cross-products.
Real Applications
Proportions are used in scaling, mixing, conversions, and many practical problems.