Ratio to Percentage
Divide each term by the sum of both. 7:3 is 70% and 30%, and the two always add to 100%.
Your numbers
A share
70%
B share
30%
Formula
A share = A ÷ (A + B) × 100
A ratio relates two values; a percentage relates one to the whole. In 7:3, the 7 is 2.33× the 3 and 70% of the total.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| AThe first number of the ratio — the 2 in 2:3. | 7 | 0 and up |
| BThe second number of the ratio — the 3 in 2:3. | 3 | 0 and up |
Step by step
Quick reference table
Results when only A changes and everything else stays put.
| A | A share (%) | B share (%) |
|---|---|---|
| 3.5 | 53.8 | 46.2 |
| 5.25 | 63.6 | 36.4 |
| 7 | 70 | 30 |
| 10.5 | 77.8 | 22.2 |
| 14 | 82.4 | 17.6 |
What each result means
| Result | At default values |
|---|---|
| A share (%)The percentage that applies to the first item. | 70 |
| B share (%)The percentage that applies to the second item. | 30 |
Common mistakes
A ratio relates two values; a percentage relates one to the whole. In 7:3, the 7 is 2.33× the 3 and 70% of the total.
Glossary
- A
- The first number of the ratio — the 2 in 2:3.
- B
- The second number of the ratio — the 3 in 2:3.
- A share
- The percentage that applies to the first item.
- B share
- The percentage that applies to the second item.
Frequently asked questions
Q. How is Ratio to Percentage calculated?
A share = A ÷ (A + B) × 100 — Divide each term by the sum of both. 7:3 is 70% and 30%, and the two always add to 100%.
Q. Can you walk through an example?
With A 7, B 3, the answer is A share 70%.
Q. What do I need to enter?
Enter A, B. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only A moves the answer to A 3.5 → A share (%) 53.8 and A 14 → A share (%) 82.4. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
A ratio relates two values; a percentage relates one to the whole. In 7:3, the 7 is 2.33× the 3 and 70% of the total.
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