Ratio simplifier
Reduce a ratio to its simplest integer form — integers, decimals, fractions and percentages all supported, reduced exactly with BigInt (1920:1080 → 16:9) — plus the greatest common divisor, decimal value and proportional scaling.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Input
Every term is parsed as an exact BigInt fraction, so decimals and fractions are cleared and reduced without any floating point drift.
Simplified ratio
1201920:10801.77777816/9177.78%Proportional scaling
48:27What this tool does
- Turn screen resolutions and photo sizes into a standard aspect ratio: enter 1920:1080 and get 16:9 for a spec sheet or a device comparison.
- Scale a recipe, paint mix or concrete mix: reduce it to the simplest integer ratio first, then use proportional scaling for the actual quantities.
- Check ratio homework: decimal and fractional ratios such as 0.5:0.75 or 1/3:1/6 are cleared and reduced exactly, so hand-calculation slips do not survive.
- Convert a ratio into a decimal or a percentage: 16:9 is 1.777778, i.e. 177.78%, which makes comparisons with other ratios straightforward.
Example
Input
1920:1080 (scale factor 3)
Output
Simplest integer ratio 16:9, common divisor removed 120, integer terms 1920:1080, decimal value 1.777778, fraction form 16/9, percentage form 177.78%; scaling by 3 gives 48:27
The greatest common divisor of 1920 and 1080 is 120, so dividing both sides by 120 gives 16:9. Entering 0.5:0.75 yields 2:3 and 1/3:1/6 yields 2:1.
Frequently asked questions
How are decimal ratios simplified?
Each term is parsed as an exact rational number: 0.5 becomes 1/2 and 0.75 becomes 3/4, the denominators are cleared with their least common multiple to get 2:3, and the result is reduced by the greatest common divisor. All of it runs on BigInt integers, so even a ratio like 0.1:0.2 comes out exact.
Can I use percentages as ratio terms?
Yes. 50% is first read as 50/100, that is 1/2, so 100%:50% reduces to 2:1. Remember that inside a ratio a percentage is just another way to write the same number — it does not have to add up to 100%.
Can ratios with more than two terms be simplified?
Yes, up to 8 terms. All terms are cleared of denominators together and then divided by the greatest common divisor of the resulting integers, so 4:6:8 becomes 2:3:4. The decimal, fraction and percentage fields are only produced for two-term ratios.
Why can ratio terms not be negative?
A ratio describes the relative size of quantities of the same kind — lengths, parts, a scale factor. Negative terms make the comparison meaningless and leave the sign handling of the greatest common divisor ambiguous, so the tool refuses instead of returning something that could be misread.
What is the "common divisor removed" figure for?
It is the factor between the integer terms and the simplest ratio — 120 for 1920:1080. That makes real-world scaling easier: divide your target width by 120 and multiply by 16 to get the matching height without reducing the ratio again.
Keywords：ratio simplifiersimplify ratioaspect ratiogreatest common divisor16:9比例化简最简整数比约分最大公约数长宽比1920x1080