Aspect Ratio Calculator
Calculate dimensions, resize proportionally
16:9
Decimal: 1.7778
Presets
Common Resolutions
HD (720p)1280 × 720
Full HD (1080p)1920 × 1080
2K (1440p)2560 × 1440
4K (2160p)3840 × 2160
Instagram Post1080 × 1080
Instagram Story1080 × 1920
Twitter Header1500 × 500
Facebook Cover820 × 312
OG Image1200 × 630
A4 (300dpi)2480 × 3508
How to use Aspect Ratio Calculator
- Enter width and height in pixels to see the simplified ratio.
- Click a preset to apply common aspect ratios (16:9, 4:3, 1:1, etc.).
- Click a common resolution to fill in exact dimensions.
- The visual preview shows the proportional shape of your dimensions.
Understanding aspect ratios
Aspect ratios define the proportional relationship between width and height. They are fundamental to photography, videography, web design, and print design. Using the wrong ratio leads to stretched, cropped, or distorted content.
The most important ratios to know: 16:9 for widescreen video (YouTube, TV), 9:16 for vertical mobile video (TikTok, Instagram Reels), 1:1 for square content (Instagram feed, profile pictures), and 3:2 for standard photography.
When resizing images, maintaining the aspect ratio prevents distortion. Enter one dimension and the tool calculates the other to keep the proportions correct.
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio is the proportional relationship between width and height. 16:9 means for every 16 units of width, there are 9 units of height. It describes shape, not size.
What is the most common aspect ratio?
16:9 (widescreen) is the standard for monitors, TVs, and YouTube videos. 9:16 is standard for mobile/vertical video (TikTok, Reels, Shorts). 1:1 is used for Instagram posts and profile pictures.
How do I calculate aspect ratio from pixel dimensions?
Divide both width and height by their greatest common divisor (GCD). For example, 1920x1080: GCD is 120, so 1920/120 : 1080/120 = 16:9.
What aspect ratio should I use for printing?
Common print ratios: 3:2 (standard photos, 4x6 prints), 4:3 (8x10 prints), 5:4 (8x10 prints), 7:5 (5x7 prints). Check with your printer for exact requirements.