How to use Ratio Calculator
Simplify a ratio and solve a missing proportion.
- Choose the operation and enter every labeled input, keeping units and the time period consistent.
- Calculate, compare the worked example below and inspect any warnings.
- Change one assumption to compare another scenario; keep the model’s limits in view.
Formula & calculation method
Simplify A:B by dividing both whole-number terms by their greatest common divisor. For A:B = C:D, solve D = C × B ÷ A.
Input reference · 4 fields
These labels describe the calculation’s base units. Supported measurements can switch through the header’s region settings; follow the current workspace labels. Prefilled values are examples.
- Calculation
- Choose: Simplify A:B, Solve A:B = C:D.
- A
- Enter a plain number with a decimal point if needed. The workspace shows an illustrative value, not a recommendation.
- B
- Enter a plain number with a decimal point if needed. The workspace shows an illustrative value, not a recommendation.
- C (for proportion)
- Enter a plain number with a decimal point if needed. The workspace shows an illustrative value, not a recommendation.
A quick example
12:18 simplifies to 2:3.
Assumptions, edge cases & limits
- A and B must be non-negative whole numbers within safe integer limits.
- 0:0 is undefined; solving a proportion requires A to be greater than zero.
- A zero-to-zero ratio is undefined.
Questions about Ratio Calculator
How do I simplify a ratio such as 12:18?
Choose Simplify A:B and enter 12 and 18. Their greatest common divisor is 6, so the simplified ratio is 2:3.
Can the missing value in a proportion be a decimal?
Yes. The solved value C × B ÷ A can be fractional even when A and B are whole numbers. Check whether your real-world use needs whole-item rounding.
Are my files or inputs uploaded?
Calculation and file processing run in your browser without a processing upload. Downloads go to your device. Choosing a next-step transfer creates a temporary local copy for that workflow. Region preferences are stored separately from tool inputs. See our privacy details.
Can I use this tool for free?
Yes. No signup, subscription or payment is required to use the tool or download its output. File tools have device and size limits; a smaller batch may work better on a phone.
A result or explanation needs correcting? Tell us the tool name and an example.