Math

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Equivalent Ratio Calculator.

Scale both parts of a ratio by a positive factor.

On-device calculationNo signup
01

Set your values

Results update as you type.

first: 8

first

0.000000
second: 12

second

0.000000
ratio: 8:12

ratio

8:12

Results update automatically as you type.

Use Cases

Recipe Scaling

Adjust ingredient quantities while keeping the same proportions. Enter the original ingredient ratio and the scale factor to get the new amounts.

Example: A recipe calls for 2 cups flour to 3 cups sugar. Scale by 2 to get 4:6.

Mixing Solutions

Maintain the correct concentration when preparing larger or smaller batches of a mixture.

Example: A 1:4 ratio of concentrate to water scaled by 5 gives 5:20.

Frequently Asked Questions

What does the Equivalent Ratio Calculator do?
It takes a ratio (First part and Second part) and a Scale factor, then multiplies both parts by that factor to produce an equivalent ratio. For example, 2:3 scaled by 4 becomes 8:12.
Can I use any positive number as the scale factor?
Yes, the calculator accepts any positive number for the scale factor. Multiplying both parts by the same positive number always yields an equivalent ratio.
What if I enter a negative scale factor?
The calculator is designed for positive scale factors only. Negative factors would reverse the ratio's direction and are not supported here.

Tips & Common Mistakes

Tips

  • Ensure both parts are positive numbers; the calculator expects a valid ratio.
  • Use a scale factor greater than 1 to enlarge the ratio, or between 0 and 1 to reduce it.
  • Double-check your inputs: the scale factor multiplies both parts, so a small error can change the result significantly.

Common Mistakes to Avoid

  • Entering a negative scale factor, which is not allowed and may produce an error.
  • Confusing the scale factor with the ratio itself—remember it's the multiplier, not a part of the ratio.
  • Forgetting to simplify the resulting ratio if needed; the calculator gives the scaled version, not necessarily in simplest form.

Last updated: August 13, 2026