Portrait Aspect Ratio
Calculate the portrait aspect ratio of any image or video from width and height. Get simplified ratio, closest standard portrait ratio, and orientation with free online charts.
About This Calculator
The Portrait Aspect Ratio Calculator helps photographers, videographers, social media creators, and designers determine the portrait aspect ratio of any image or video. Simply enter the width and height in pixels, and the calculator instantly computes the simplified ratio (e.g., 9:16 or 2:3), decimal ratio, and identifies the closest standard portrait aspect ratio.
Aspect ratio is calculated by dividing the width by the height (width ÷ height). The calculator then finds the greatest common divisor (GCD) to simplify the ratio to its lowest terms, such as 9:16, 2:3, or 4:5. It also identifies the orientation (portrait, landscape, or square) and matches your ratio against common portrait standards used in photography, social media, and video production.
Common Portrait Aspect Ratios
9:16 (0.5625) — The standard for vertical video on TikTok, Instagram Reels, YouTube Shorts, and Snapchat. This is essentially 16:9 rotated to vertical orientation and is the most popular portrait video format.
2:3 (0.6667) — Classic portrait photography ratio inherited from 35mm film cameras. Many DSLR and mirrorless cameras capture in this ratio by default.
4:5 (0.8) — Standard portrait print size (8×10 inches). Also used by Instagram portrait posts and micro four-thirds cameras. Provides a balanced vertical composition.
3:4 (0.75) — Common in micro four-thirds camera systems and some smartphone cameras. Also used for certain print sizes like 6×8 inches.
Regional Notes
Global: Portrait aspect ratios are universal across all regions, driven by smartphone photography, social media platforms, and printing standards. The 9:16 ratio dominates social video globally on platforms like TikTok and Instagram.
Frequently Asked Questions
What is a portrait aspect ratio?
A portrait aspect ratio refers to the proportional relationship between width and height of an image or video where the height is greater than the width. Common portrait ratios include 9:16 (vertical video), 2:3 (classic portrait photo), 4:5 (standard portrait), and 3:4 (micro four thirds). Portrait orientation is the opposite of landscape where width exceeds height.
How do I calculate a portrait aspect ratio?
To calculate a portrait aspect ratio, divide the width by the height to get the decimal ratio, then simplify using the greatest common divisor (GCD). For example, an image of 1080 pixels wide by 1920 pixels tall gives 1080/1920 = 0.5625, which simplifies to 9:16 (the standard vertical video ratio).
What are the most common portrait aspect ratios?
The most common portrait aspect ratios are 9:16 (vertical video for TikTok, Instagram Stories, and YouTube Shorts), 2:3 (classic portrait photography using 35mm film), 4:5 (standard portrait print size 8x10 inches), 3:4 (micro four thirds cameras), and 5:7 (classic print size). Each serves different media and photography needs.
Is 4:5 aspect ratio good for portrait photography?
Yes, 4:5 aspect ratio is excellent for portrait photography. It is the standard for 8x10 inch prints and is commonly used by micro four thirds cameras and film photographers. The 4:5 ratio provides a pleasing vertical composition that works well for individual and group portraits alike.
What is the difference between portrait and landscape aspect ratios?
The key difference is orientation: portrait aspect ratios have height greater than width (e.g., 9:16, 2:3, 4:5), while landscape ratios have width greater than height (e.g., 16:9, 4:3, 21:9). Portrait orientation is ideal for vertical content like phone photos, social media stories, and printed portraits, while landscape suits widescreen video and horizontal compositions.
How do I resize an image to a specific portrait aspect ratio?
To resize an image to a specific portrait aspect ratio, if you know the height, multiply it by the target ratio (width/height) to get the required width. For example, for a 2:3 ratio image with 600px height, multiply 600 by 2/3 to get 400px width. Conversely, if you know the width, divide by the ratio to find the height.
Why is 9:16 called the portrait aspect ratio for video?
9:16 is called the portrait aspect ratio for video because it is the vertical orientation used by most modern smartphones and social media platforms. Platforms like TikTok, Instagram Reels, YouTube Shorts, and Snapchat all use 9:16 as their standard format. It is essentially the 16:9 widescreen ratio rotated 90 degrees for vertical viewing.
How can I find the closest standard portrait ratio for my image?
The portrait aspect ratio calculator automatically compares your image's decimal ratio against common portrait standards including 9:16 (0.5625), 2:3 (0.6667), 3:4 (0.75), 4:5 (0.8), 5:7 (0.714), and 10:16 (0.625). It identifies the closest match, helping you select the optimal crop or resize target for your project.