About the Ratio Calculator
Reduce any ratio to its simplest whole-number form, or solve a proportion to find a missing value. Handy for screen sizes, recipes, scale models and mixing ratios.
Key features
- Simplify any ratio to whole numbers (1920:1080 → 16:9)
- Works with decimals and three or more terms
- Solve proportions A:B = C:x for the missing value
- Decimal form (n : 1) shown
- Great for screens, recipes, maps and mixtures
- Instant results
Simplify and solve ratios
Ratios describe how quantities relate: screen aspect ratios, recipe proportions, map scales, paint and fuel mixtures, and gear ratios. This calculator simplifies ratios and solves proportions to find missing values.
Common aspect ratios
| Resolution | Simplified ratio | Typical use |
|---|---|---|
| 1920 × 1080 | 16:9 | HD video, monitors, YouTube |
| 3840 × 2160 | 16:9 | 4K UHD |
| 1080 × 1350 | 4:5 | Instagram portrait posts |
| 1080 × 1920 | 9:16 | Stories, Reels, TikTok |
| 1024 × 768 | 4:3 | Older displays, iPad |
| 2560 × 1080 | 64:27 (≈ 21:9) | Ultrawide monitors |
Solving proportions
To scale while keeping the same ratio, solve A : B = C : x:
x = B × C ÷ A
Example: a recipe uses 2 cups of flour for 3 eggs. How many eggs for 10 cups? 2 : 3 = 10 : x → x = 3 × 10 ÷ 2 = 15 eggs.
Everyday uses
- Resizing images without distortion.
- Scaling recipes up or down.
- Mixing ratios: two-stroke fuel (50:1), concrete (1:2:3), cleaning solutions.
- Map scales: 1:50,000 means 1 cm on the map is 500 m on the ground.
Related calculators
Work with fractions in the Fraction Calculator or percentages in the Percentage Calculator.
How to use the Ratio Calculator
- Enter your numbers in the fields above. Units and options can be changed at any time.
- The result updates instantly as you type; there's no calculate button to press.
- Check the breakdown under the main result for the details behind the number.
- Adjust the inputs to compare scenarios, for example a different rate or term.