Updated · Methodology: named formula library
Ratio Calculator
Solve ratio proportions: if A:B = C:?
A to B = 2:1 (2 as decimal).
Why This Calculation Matters
The Ratio Calculator gives you a fast, accurate answer for ratio, useful for homework, coursework, or inside a larger problem. The formula is shown below so you can see exactly what the tool is doing and verify it against a textbook or other reference.
How to Use This Calculator
- Enter your values in the input fields, each one has a label and help text explaining what to type.
- Results appear instantly as you type; there's no "calculate" button to press.
- Change any input to compare scenarios side by side.
All math happens in your browser. Nothing you type is sent to a server, saved, or shared.
How to Use the Ratio Calculator
Enter the required values in the input fields on the left. Results update instantly on the right as you adjust your inputs.
Understanding Your Results
Review each output value and its description to understand how your inputs affect the outcome. Adjust values to compare different scenarios.
Tips
- All calculations happen in your browser, your data is never stored
- Bookmark this page for quick access
- Try different values to see how results change
Worked Example
100 A to 50 B
- a
- 100
- b
- 50
- Result
- 2:1 (2.00)
100 / 50 = 2.00. Simplified: 2:1.
When to Use This Calculator
- Check homework, textbook problems, or coursework answers.
- Explore how the result changes as you vary inputs, great for intuition building.
- Verify a calculation inside a larger engineering, research, or data workflow.
Limitations & Common Mistakes
- Results are only as accurate as the inputs, double-check rounding and units.
- Numeric precision is limited by JavaScript floating-point arithmetic.
Frequently Asked Questions
How is the Ratio Calculator computed?
A divided by B, plus a simplified ratio (e.g., 4:3) using greatest common divisor. Both decimal and ratio forms are useful in different contexts: decimal for math, ratio form for comparisons or recipe scaling.
What does A:B mean?
It's a comparison: for every B unit, you have a corresponding amount of A. Useful when the absolute numbers matter less than the proportion (e.g., reading 8:1 LTV/CAC immediately tells you the unit economics are healthy without needing the dollar amounts).
Why simplify the ratio?
4:3 is more readable than 200:150. The simplified form (using greatest common divisor) preserves the proportion while making it easier to interpret. Common simplified ratios: 16:9 (widescreen), 4:3 (legacy displays), 3:1 (LTV:CAC for SaaS).
When is a ratio more useful than the absolute values?
Comparison across scales. A $1B company and a $1M company can both have a 3:1 LTV:CAC; the ratio reveals comparable unit economics regardless of scale. Use ratios for benchmarking; use absolute numbers for budgeting.
Related Calculators
More Math →Source: BLS Consumer Price Index, 2026.