Quick start
- Choose Simplify, Equivalent, or Split total.
- Enter the ratio parts or known values for the selected mode.
- Press Calculate ratio.
- Review the answer, scale factor or shares, and step-by-step work.
- Use examples, recent answers, or Copy answer while checking proportions.
Simplify mode
Simplify mode reduces a two-part or three-part ratio to lowest terms. For 12:18, the greatest common divisor is 6, so the simplified ratio is 2:3.
Decimal ratios are allowed. The calculator first clears the decimal places, then simplifies the whole-number version.
Equivalent mode
Equivalent ratios keep the same relationship between parts. If 4:7 becomes 20:?, the first part was multiplied by 5, so the second part is also multiplied by 5. The answer is 20:35.
Split total mode
Split total mode divides an amount by ratio parts. For 100 split by 2:3, there are 5 total parts. One part is 20, so the shares are 40 and 60.
This is useful for recipes, classroom examples, group shares, mixtures, and simple proportional planning.
Examples from the ratio calculator
2:3
20:35
40, 60
Common mistakes
Keep ratio parts in the same order. A ratio of 2:3 is not the same as 3:2 because the parts describe different shares.
Do not mix units without converting first. For example, compare inches to inches or centimeters to centimeters before simplifying a measurement ratio.
History, privacy, and copying
Recent ratio answers stay visible in the page while you work. The history is kept only in the current browser tab and is not sent to a server.
Copy answer copies the ratio expression and result so you can paste it into notes, homework, a message, or another document.