About the Ratio Calculator
What is the Ratio Calculator?
A ratio compares two quantities by division. A ratio of 3 : 2 means that for every 3 units of the first quantity there are 2 of the second. Ratios are used to share profits between partners, mix ingredients or concrete, scale drawings and maps, and compare financial figures.
This calculator reduces A : B to its simplest whole-number form (decimals are scaled up first), expresses each side as a percentage of the total, gives the decimal value of A ÷ B and, if you enter an amount, divides that amount between A and B in the same ratio.
How to use the Ratio Calculator
- First Quantity (A) — any positive number, whole or decimal. (sample: 45)
- Second Quantity (B) — any positive number, in the same unit as A. (sample: 30)
- Amount to Split in This Ratio (optional) — optional amount to divide between A and B; enter 0 to skip. (sample: 1,000)
- Press Simplify Ratio (results also refresh as you type). The result card shows the Simplified Ratio, along with A as a share, B as a share, A ÷ B and A's part of 1,000.
Formula used
A : B = (A ÷ g) : (B ÷ g)
- g = the greatest common divisor of A and B
- Share of A = Amount × A ÷ (A + B)
For decimal inputs such as 1.5 : 2.25, both sides are first multiplied by a power of 10 to make them whole numbers (150 : 225), then simplified to 2 : 3.
Worked example
These are the sample values already filled in the calculator above, and the result it returns for them:
| Input | Sample value |
|---|---|
| First Quantity (A) | 45 |
| Second Quantity (B) | 30 |
| Amount to Split in This Ratio (optional) | 1,000 |
| Result | Value |
|---|---|
| Simplified Ratio | 3 : 2 |
| A as a share | 60% |
| B as a share | 40% |
| A ÷ B | 1.5 |
| A's part of 1,000 | 600 |
| B's part of 1,000 | 400 |
Tips for using the Ratio Calculator
- Ratios have no units, but both quantities must be in the same unit first: 1 m : 50 cm becomes 100 cm : 50 cm = 2 : 1.
- To split among more than two people (say 2 : 3 : 5), divide the total by the sum of the parts (10) and multiply by each part.
- Order matters — 3 : 2 is not the same as 2 : 3.