Ratio Calculator
Simplify, scale, split and compare ratios, and solve proportions A:B = C:D
Runs entirely in your browser. Nothing you type or upload is sent to us or stored.
Results are for general guidance. Please check anything important before relying on it. Terms of use
How to Use
- Choose what you want to do: simplify a ratio, scale it, solve a proportion, split an amount, or compare two ratios.
- Type ratios with a colon, like 12:18 or 2:3:5. Decimals (1.5:2.5) and fractions (1/2:1/3) work too.
- Fill in the other boxes for that option: the total or the known term when scaling, three of the four terms A, B, C, D for a proportion, or the amount in ₹ (or any quantity) when splitting.
- The answer updates as you type, with each step explained underneath. Use copy result or share to send it.
Simplify, scale, split and compare ratios
A ratio compares quantities of the same kind: 12 boys to 18 girls is 12:18, which simplifies to 2:3. This ratio calculator does the five things people most often need with ratios. It simplifies a ratio, scales it to a total or to a known term, solves a proportion A:B = C:D for the missing term, splits an amount in a given ratio, and tells you which of two ratios is bigger. Ratio and proportion are taught from Class 6 onwards and are a regular part of the quantitative aptitude section in SSC CGL, SSC CHSL and bank exams, usually as partnership, mixture and age problems.
Simplifying a ratio
Divide every term by their HCF. If the terms are decimals or fractions, first multiply every term by the same number to make them whole.
1.5 : 2.5 × 10 → 15 : 25, HCF = 5 → 3 : 5
1/2 : 1/3 × 6 → 3 : 2
A ratio with three or four terms works the same way: 4:6:10 simplifies to 2:3:5.
Scaling a ratio
To share a total in the ratio 3:5, add the terms (3 + 5 = 8 parts) and find one part. For a total of 64, one part is 64 ÷ 8 = 8, so the ratio becomes 24:40. If instead you know that the first term must become 15, the multiplier is 15 ÷ 3 = 5 and the ratio becomes 15:25.
Solving a proportion
Four numbers are in proportion when A:B = C:D. Then the product of the extremes equals the product of the means:
3 : 4 = 15 : D → D = (4 × 15) ÷ 3 = 20
This is the unitary method in a single line. If 3 kg of rice costs ₹150, then 7 kg costs 150 × 7 ÷ 3 = ₹350.
Splitting an amount
Business partners often share profit in the ratio of their investments. Suppose three friends invest ₹20,000, ₹30,000 and ₹50,000. The ratio is 2:3:5 (10 parts), so a profit of ₹50,000 is shared like this:
| Partner | Ratio term | Fraction | Share |
|---|---|---|---|
| First | 2 | 2/10 | ₹10,000 |
| Second | 3 | 3/10 | ₹15,000 |
| Third | 5 | 5/10 | ₹25,000 |
When an amount doesn't divide evenly, rupee shares are rounded to the paisa and the leftover paise go to the shares with the largest remainders, so the shares always add up to the exact amount. ₹100 split 1:1:1 becomes ₹33.34, ₹33.33 and ₹33.33. Choose "Any quantity" to split litres, kilograms or marks instead of rupees.
Comparing two ratios
To compare a:b with c:d, compare the fractions a/b and c/d by cross-multiplying. For 3:4 and 5:7: 3 × 7 = 21 and 4 × 5 = 20. Since 21 > 20, 3:4 is the larger ratio. Writing both with the same second term shows it directly: 21:28 against 20:28. If the cross products are equal, the ratios are equivalent, as 2:3 and 10:15 are.
Tips
- Put quantities in the same unit before forming a ratio: 50 paise to ₹2 is 50:200, which is 1:4, not 50:2.
- Order matters. 2:3 and 3:2 are different ratios.
- A ratio has no unit. 2:3 just says the first quantity is two-thirds of the second.