Ratio & proportion tools
2:1 Ratio Calculator
A 2:1 ratio has 3 total parts, and the first part is 66.67% of the whole, the second part is 33.33% of the whole. The ratio is already in its simplest form.
2:1
Simplest form 2:1 · 3 total parts
300
Exact result
200 units · 100 units
66.67% : 33.33% · 3 total parts · 1 part = 100 units
first part
second part
- Total parts
- 3
- Simplest form
- 2 : 1
- 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: 200 and 100.
Equivalent 2:1 ratios
- 2 : 1
- 4 : 2
- 6 : 3
- 8 : 4
- 10 : 5
- 12 : 6
What 2:1 means
A 2:1 ratio has 3 total parts. Each part is worth the total divided by 3, so the shares are 66.67% and 33.33% of whatever you are dividing.
- Total parts
- 3
- Simplest form
- 2:1
- One part of 300
- 100
Where this ratio shows up
The reverse of 1:2 — twice as much of the first quantity. Common in two-stroke fuel talk, mortar mixes and 2:1 scale drawings.
Worked example
Dividing 300 in a 2:1 ratio gives 200 and 100. Add them back together and you get 300 exactly — a quick way to check any split.