Common Presets
Calculate Ratio
Aspect Ratio
Scale Dimensions
Scaled Dimensions
Visual Preview
Enter dimensions to preview
Megapixels
Decimal Ratio
Orientation
Total Pixels
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio is the proportional relationship between the width and height of a rectangle — commonly used for images, videos, and screens. It is expressed as two numbers separated by a colon (e.g., 16:9), where the first number is the width and the second is the height.
How do I calculate the aspect ratio from width and height?
To calculate the aspect ratio, divide both the width and height by their Greatest Common Divisor (GCD). For example, for 1920×1080: GCD(1920, 1080) = 120, so 1920÷120 = 16 and 1080÷120 = 9, giving an aspect ratio of 16:9.
How do I resize an image while keeping its aspect ratio?
To resize while maintaining the aspect ratio, fix one dimension and calculate the other using the ratio. New Height = (New Width × Original Height) / Original Width. For example, to resize 1920×1080 to a width of 1280: New Height = (1280 × 1080) / 1920 = 720.
What are common aspect ratios and their uses?
- 16:9 — Widescreen TV, YouTube, most modern monitors
- 4:3 — Traditional TV, older monitors, some cameras
- 21:9 — Ultrawide monitors, cinematic movies
- 1:1 — Square (Instagram posts, profile pictures)
- 9:16 — Vertical video (TikTok, Instagram Stories, Reels)
- 3:2 — DSLR cameras, some laptops
What is the 16:9 aspect ratio in pixels?
Common 16:9 pixel resolutions include: 1280×720 (HD/720p), 1920×1080 (Full HD/1080p), 2560×1440 (QHD/2K), and 3840×2160 (UHD/4K). Any resolution where width ÷ height = 1.778 is a 16:9 ratio.