Ratio & proportion tools
1:2 Ratio Calculator
A 1:2 ratio has 3 total parts, and the first part is 33.33% of the whole, the second part is 66.67% of the whole. The ratio is already in its simplest form.
1:2
Simplest form 1:2 · 3 total parts
Exact result
100 units · 200 units
33.33% : 66.67% · 3 total parts · 1 part = 100 units
- Total parts
- 3
- Simplest form
- 1 : 2
- One part
- 100 units
Know one side instead?
Enter one measured amount to scale the whole ratio.
Working
- Add the parts: 3 total parts.
- One part = 300 ÷ 3 = 100 units.
- Multiply one part by each ratio part: 100 and 200.
Equivalent 1:2 ratios
- 1 : 2
- 2 : 4
- 3 : 6
- 4 : 8
- 5 : 10
- 6 : 12
What 1:2 means
A 1:2 ratio has 3 total parts. Each part is worth the total divided by 3, so the shares are 33.33% and 66.67% of whatever you are dividing.
- Total parts
- 3
- Simplest form
- 1:2
- One part of 300
- 100
Where this ratio shows up
Common in cooking and concrete work — one part of the first ingredient for every two of the second, so the first is always half the second.
Worked example
Dividing 300 in a 1:2 ratio gives 100 and 200. Add them back together and you get 300 exactly — a quick way to check any split.