Ratio to Percentage Calculator
Last reviewed on 2026-05-22.
Convert any ratio to its equivalent percentage
How it works
A ratio expresses parts of a whole. To convert a ratio to percentages, sum the parts to get the total, then divide each part by the total and multiply by 100. For a 3:7 ratio, the total is 10. Part A is 3/10 = 30%; Part B is 7/10 = 70%.
Why this matters for pie charts
Many real-world data sources express splits as ratios (3:1 male:female, 2:5 wins:losses, 1:9 conversions:non-conversions). To plot them as a pie chart, you need the percentages. This calculator does the conversion in one keystroke.
Multi-part ratios
For ratios with 3+ parts (like 4:3:2), the same formula applies — sum all parts, divide each by the total. For pie charts with many categories, the maker handles this automatically: enter the raw ratio values, and the chart calculates the percentages.
Part A is — of the total.
Part B is — of the total.
Frequently Asked Questions
How do I convert a ratio to a percentage?
Sum the parts, then divide each part by the total and multiply by 100. A 3:7 ratio becomes 30% and 70%.
Can a ratio have more than two parts?
Yes — the formula is the same. For a 4:3:2 ratio, total is 9; the percentages are 44.4%, 33.3%, and 22.2%.
What if the ratio uses fractions or decimals?
Works the same way. A 2.5:7.5 ratio becomes 25% and 75%.