Ratio & proportion tools
Percentage to Ratio Calculator
Choose what your percentage means, then get the matching ratio in its simplest form.
Exact result
1 : 4
25% of the whole, written as part : whole
Working
- Chosen meaning: part : whole → 25:100.
- Divide both parts by the GCD 25 → 1:4.
- The other meaning would give 1:3.
One percentage, two possible ratios
A percentage always compares something with 100. Turning it into a ratio forces a decision the percentage never had to make: is the second term the whole, or is it everything that is left over?
25%
Part to whole: 25 : 100 → divide both by 25 → 1:4. One part in every four.
Part to remainder: 25 : 75 → divide both by 25 → 1:3. One part for every three of the rest.
Both are correct descriptions of the same 25% — they use different second terms.
A quick check: in the part-to-whole form the parts sum to the whole, so 1:4 means one of the four is your share. In the part-to-remainder form the parts sum to more than the whole would suggest — 1:3 is four parts in total, and your share is one of them, still 25%.
Conversion reference
| Percentage | Part to whole | Part to remainder | Reads as |
|---|---|---|---|
| 10% | 1:10 | 1:9 | 1 in every 10 |
| 12.5% | 1:8 | 1:7 | 1 in every 8 |
| 20% | 1:5 | 1:4 | 1 in every 5 |
| 25% | 1:4 | 1:3 | 1 in every 4 |
| 33⅓% | 1:3 | 1:2 | 1 in every 3 |
| 50% | 1:2 | 1:1 | 1 in every 2 |
| 60% | 3:5 | 3:2 | 3 in every 5 |
| 75% | 3:4 | 3:1 | 3 in every 4 |
Part-to-whole compares the share with the total; part-to-remainder compares it with what is left.
The wording of your source decides the column. “25% of the mixture” is part to whole. “One part concentrate for every three parts water” is part to remainder, even though it also describes 25%. Confusing the two shifts every downstream quantity.
Percentages above 100%
Part to whole still works: 150% is 150:100, or 3:2. Part to remainder does not, because there is no remainder left to compare with — the calculator reports that rather than returning a negative part.