Ratio Calculator
Simplify ratios, scale ratios, and solve ratio problems.
D (Missing Term)
12.00
Simplified
3.00:4.00
Ratio Details
| Original Ratio | 3:4 |
| Equivalent | 9:12.00 |
Use the Ratio Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.
Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.
How It Works
Our Ratio Calculator is your essential tool for understanding and manipulating proportional relationships. It simplifies complex ratios to their most basic form, scales ratios to meet specific needs, and solves for unknown variables in ratio problems. In 2026, with an estimated global population of 8.3 billion and a projected 3.5% annual growth in e-commerce, understanding ratios is more critical than ever for analyzing market shares, resource allocation, and demographic trends.
This calculator employs fundamental principles of proportionality. For simplification, it identifies the greatest common divisor (GCD) between the ratio's terms and divides each term by the GCD. For scaling, it multiplies or divides each term by a specified factor to maintain the original proportion. When solving for an unknown, it utilizes cross-multiplication, where if a/b = c/d, then ad = bc, allowing for the isolation of the unknown variable.
Always ensure your units are consistent when working with ratios, as mixing units can lead to incorrect results. A common mistake is simplifying ratios incorrectly by not finding the greatest common divisor, or by only simplifying one side of the ratio. Remember that ratios represent a relationship, not absolute quantities, so scaling affects both parts of the relationship proportionally.
Example: Scaling a Recipe for a 2026 Charity Event
- 1 A recipe for 10 servings requires 2 cups of sugar and 3 cups of flour. We need to scale this recipe to serve 75 people for a charity event in 2026. Input the initial ratio: Sugar (2) : Flour (3) and the desired number of servings (75).
- 2 The calculator first determines the scaling factor by dividing the desired servings (75) by the original servings (10), which is 7.5. It then multiplies each term of the original ratio by this scaling factor: 2 cups * 7.5 = 15 cups of sugar, and 3 cups * 7.5 = 22.5 cups of flour.
- 3 The scaled ratio is 15 cups of sugar : 22.5 cups of flour. This means for 75 servings, you will need 15 cups of sugar and 22.5 cups of flour.
- 4 This scaled recipe ensures that the taste and consistency remain the same for the larger crowd at your 2026 charity event, demonstrating the practical application of ratio scaling in everyday scenarios, from cooking to large-scale resource planning.
Source: Khan Academy · Last updated: April 2026
Frequently Asked Questions
How do I simplify a ratio?
How do I scale a ratio up or down?
What is the difference between a ratio and a fraction?
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