Ratio Calculator
Math CalculatorsSolve A:B=C:D, simplify ratios and allocate proportionally
Quick Answer
Ratio Calculator: Solve A:B=C:D, simplify ratios and allocate proportionally. Solve A:B=C:D → D = B×C ÷ A (cross-multiplication).
D = B × C ÷ A16.0000
Simplest integer ratio3.00 : 4.00
Check: 3 : 4 = 12 : 16.0000 — cross products equal: A×D = B×C.
Ratios in everyday life
| Scenario | Ratio |
|---|---|
| Concrete (cement:sand:gravel) | 1:2:3 |
| Screen aspect ratio | 16:9 |
| Map scale | 1:50,000 |
| Golden ratio | 1 : 1.618 |
| Rice cooking (rice:water) | 1 : 1.2 |
A ratio compares parts to each other, a percentage compares one part to the whole — 2:3 means 40%/60%, not 66.7%. When splitting money, always check that the rounded shares still add up to the total.
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How to Use
- Enter values or expressions: type directly into the Ratio Calculator — keyboard friendly.
- Instant results: everything computes live as you type, no button needed.
- Follow the steps: the result panel shows full working and formula substitution.
- Copy or recompute: one-click copy; change any input to recalculate instantly.
Key Points
- Ratio Calculator is a free online math tool — open and use, no sign-up.
- All calculations run locally in your browser; your data never leaves the device.
- Key capability: Solve A:B=C:D, simplify ratios and allocate proportionally.
- Results come with formulas and reference tables so you can verify every number.
Formula & How It Works
Ratio
Solve A:B=C:D → D = B×C ÷ A (cross-multiplication)
Allocate total T by a:b:c → part i = T × aᵢ ÷ Σa
Simplify: divide all terms by GCD
FAQ
How do I use the Ratio Calculator?
Open the page and fill in the input fields — results update automatically. Solve A:B=C:D, simplify ratios and allocate proportionally.
Are the results accurate?
Yes. All calculations use standard mathematical formulas and are verified for accuracy.
Is it free? Do I need to sign up?
Completely free. No registration, login or download required — just open and use.
Does it work on mobile?
Yes. The responsive design works on phones, tablets and desktops.
Is my data saved?
No. All calculations run locally in your browser. Nothing is uploaded or stored.
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Source & Updates
Standard mathematical formulas. All logic verified. Last updated: 2025-07
Last updated:
Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.
Maintained and periodically reviewed by the YiJianSuan editorial team — review process in ourEditorial Policy.
Cite this page: YiJianSuan. Ratio Calculator[EB/OL]. https://www.yijiansuan.com/en/c/math/ratio
Results provided by this tool are for reference only and do not constitute professional advice.