1920 × 1080
- Ratio = 16:9
- Decimal ≈ 1.78
tech calculator
Aspect Ratio Calculator
Reduce dimensions to a simple ratio and decimal aspect for screens or images.
Results
- Ratio width
- 16.00
- Ratio height
- 9.00
- Decimal aspect
- 1.78
How to use this calculator
- Enter width and height in pixels (or any consistent unit).
- We simplify to the smallest whole-number ratio (e.g., 16:9).
- See the decimal aspect to compare against targets like 1.77 or 1.6.
Inputs explained
- Width
- Horizontal dimension in pixels or any consistent unit.
- Height
- Vertical dimension in the same unit as width.
How it works
We reduce width and height by their greatest common divisor.
Decimal aspect helps compare widescreen vs portrait layouts.
Formula
Ratio = width ÷ GCD(width, height) : height ÷ GCD(width, height)
When to use it
- Checking if footage is 16:9, 4:3, or another standard aspect.
- Planning responsive UI layouts or artboards.
- Sizing thumbnails or exports without black bars or stretching.
Tips & cautions
- Keep units consistent—pixels, inches, or centimeters all work if both inputs match.
- If numbers are large, the reduced ratio will still match standard formats if divisible.
- Use the decimal aspect to compare to platform requirements (e.g., 1.91:1 for social feeds).
- Does not enforce target resolutions or file sizes—only ratios.
- Ignores pixel density (PPI/DPI); that depends on physical size and display.
- Cropping or scaling to hit a target ratio still needs an editing tool.
Worked examples
1080 × 1080
- Ratio = 1:1
- Decimal = 1.0
Deep dive
This aspect ratio calculator reduces width and height to a simplified ratio and decimal aspect. Enter dimensions to see if you’re at 16:9, 4:3, 1:1, or a custom format.
Use it for video exports, UI layouts, printing, and social media crops so you can match platform requirements without guessing. Keep units consistent—pixels or inches both work.
FAQs
- What if the ratio isn’t a clean whole number?
- Large dimensions that share a GCD will still reduce to clean integers. If not, the ratio will stay proportional (e.g., 1001:1000) and the decimal shows the aspect precisely.
- Does pixel density (PPI/DPI) affect aspect ratio?
- No. Aspect ratio is purely width vs. height. PPI/DPI matters for print size and sharpness, not ratio.
- Can I use centimeters or inches instead of pixels?
- Yes—any consistent unit works because the ratio is unitless.
- How do I crop to a target aspect ratio?
- Use this to identify your current ratio, then crop or resize in an editor to the desired ratio (e.g., 16:9 or 1:1).
- What’s the difference between resolution and aspect ratio?
- Resolution is total pixel count (e.g., 1920×1080). Aspect ratio is their proportion (16:9) and does not indicate sharpness on its own.
Related calculators
Pure ratio math only—does not account for codec, scaling, or platform-specific export rules.