宽高比计算器

本宽高比计算器在保持正确比例的同时计算和转换显示尺寸。输入宽度和高度以找到宽高比，或输入比例和一个尺寸来计算另一个尺寸，适用于视频、照片和屏幕分辨率。

Aspect Ratio Calculator

Calculate and convert between aspect ratios and pixel dimensions. Lock the ratio to maintain proportions while adjusting values.

Common Presets

Dimensions

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Pixels

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常见问题

什么是宽高比？

宽高比是图像、视频或屏幕的宽度与高度之间的比例关系，以冒号分隔的两个数字表示，如 16:9 或 4:3。第一个数字代表宽度，第二个代表高度。宽高比描述显示器的形状，而非尺寸。16:9 的比例意味着每 16 个宽度单位对应 9 个高度单位。

最常见的宽高比是什么？

最常见的宽高比是 16:9（也写作 1.78:1），是 HDTV、大多数电脑显示器和 YouTube 等在线视频平台的标准。其他常见比例包括 4:3（传统电视和早期显示器）、21:9（超宽显示器和电影）、1:1（正方形，用于社交媒体）和 9:16（竖向视频，用于 TikTok 和 Instagram Stories 等移动平台）。

如何根据尺寸计算宽高比？

根据像素尺寸计算宽高比时，将宽度和高度都除以它们的最大公约数（GCD）。例如，对于 1920×1080：1920 和 1080 的 GCD 为 120，两者都除以 120 得到 16:9。也可以将宽度除以高度得到小数比：1920/1080 = 1.778，对应 16:9。这种方法适用于任何分辨率。

1920×1080 的宽高比是多少？

1920×1080 像素的宽高比为 16:9，是标准全高清（1080p）分辨率。其他常见 16:9 分辨率包括 1280×720（720p HD）、2560×1440（1440p QHD）和 3840×2160（4K UHD）。16:9 是显示器、电视和视频内容最广泛使用的宽高比，在水平和垂直观看区域之间提供了良好平衡。

如何在保持宽高比的同时调整图像大小？

在保持宽高比的同时调整图像大小，改变一个尺寸并按比例计算另一个。公式：新高度 = 新宽度 × (原始高度 / 原始宽度)。例如，将 1920×1080 图像调整为 1280 像素宽：1280 × (1080/1920) = 720 像素高。大多数图像编辑器在锁定宽高比或按住 Shift 调整大小时会自动执行此操作。

16:9 和 4:3 有什么区别？

16:9 更宽更矮（宽屏），而 4:3 更接近正方形（标准）。相同对角线尺寸下，16:9 屏幕比 4:3 宽约 13%，但矮约 25%。16:9 是现代 HD 和 4K 内容的标准，而 4:3 曾是模拟电视和早期电脑显示器的标准。当 4:3 内容在 16:9 屏幕上显示时，两侧会出现黑边（左右加黑边）。

智能手机使用什么宽高比？

大多数现代智能手机在横向模式下使用 19.5:9 至 20:9 的宽高比（竖向模式为 9:19.5 至 9:20）。常见智能手机比例包括 19.5:9（iPhone）、20:9（三星 Galaxy）和 19:9。老款智能手机使用 16:9。折叠屏手机展开时可能接近 4:3。为移动端创建内容时，竖向 9:16 是 Stories 和短视频的标准。

YouTube 应该使用什么宽高比？

YouTube 使用 16:9（1920×1080）作为标准宽高比。竖向视频应使用 9:16（1080×1920）用于 Shorts。如果上传其他比例，YouTube 会添加黑边（上下加黑边或左右加黑边）来适配。

Instagram 的最佳宽高比是多少？

Instagram 支持多种比例：1:1（1080×1080）用于正方形帖子，4:5（1080×1350）用于竖向帖子（在 Feed 中占据最多屏幕空间），9:16（1080×1920）用于 Stories 和 Reels。为最大化参与度，Feed 帖子使用 4:5。

2560×1600 的宽高比是多少？

2560×1600 的宽高比为 16:10（即 8:5）。这常见于 MacBook Pro 显示屏和一些戴尔/惠普显示器。计算方法：将两个尺寸都除以最大公约数（GCD）：2560÷160 = 16，1600÷160 = 10。

Common Aspect Ratios Reference Table

The table below lists every major aspect ratio you will encounter in video production, photography, web design, and social media. Use it as a quick-reference when choosing dimensions for your project.

Table of Contents

Aspect Ratio Comparison Chart

This comprehensive table covers all standard aspect ratios used in video, photography, cinema, and digital media. The decimal value lets you compare how wide or tall each format is relative to a square (1.0).

RatioDecimalCommon ResolutionsUse Case
9:160.56251080×1920TikTok, Instagram Reels, YouTube Shorts
4:50.81080×1350Instagram portrait posts
1:11.01080×1080Instagram posts, profile pictures
4:31.331024×768, 1600×1200Classic TV, iPad, presentations
3:21.51080×720, 6000×4000DSLR photos, 35mm film
16:101.61920×1200, 2560×1600MacBook, widescreen monitors
16:91.781920×1080, 3840×2160HDTV, YouTube, modern monitors
1.85:11.851998×1080US theatrical standard
21:92.332560×1080, 3440×1440Ultrawide monitors, cinema
2.35:12.351920×817Anamorphic widescreen cinema
2.39:12.394096×1716Modern cinema (Scope)

Video Aspect Ratios (16:9, 4:3, 21:9)

16:9is the universal standard for HD and 4K video. Every major streaming platform, broadcast network, and video camera defaults to 16:9. Common resolutions include 1280×720 (720p), 1920×1080 (1080p Full HD), 2560×1440 (1440p QHD), and 3840×2160 (4K UHD).

4:3was the standard aspect ratio for television from the 1940s through the early 2000s. Today it is still used on iPads, some security cameras, and presentation slide formats (1024×768, 1600×1200). Old TV shows and classic films were shot in 4:3 and will show black bars (pillarboxing) on modern 16:9 screens.

21:9(ultrawide) is popular for immersive gaming monitors and cinematic video content. Ultrawide displays at 2560×1080 or 3440×1440 provide a wider field of view that closely matches theatrical cinema proportions.

Photography Aspect Ratios (3:2, 4:5, 1:1)

3:2is the native aspect ratio of 35mm film and most DSLR/mirrorless cameras. Standard print sizes like 4×6 inches and 6×9 inches maintain this ratio. Professional photographers typically shoot in 3:2 and crop to other ratios during post-processing.

4:5(portrait orientation) is the tallest ratio Instagram allows for feed posts at 1080×1350 pixels. It occupies more vertical screen space in the feed than a square or landscape image, which can increase engagement. The 8×10 inch print size also uses a 4:5 ratio.

1:1(square) became iconic through Instagram's original square-only format. At 1080×1080 pixels it remains a popular choice for profile pictures, album art covers, and e-commerce product images where a consistent grid layout is desired.

Cinema Aspect Ratios (2.35:1, 2.39:1, 1.85:1)

2.35:1 (anamorphic widescreen, also called CinemaScope) uses special anamorphic lenses to squeeze a wide image onto standard 35mm film and then unsqueeze it during projection. This ratio is favored for epic landscapes and action sequences.

2.39:1 (Scope) is the modern successor to 2.35:1 and the most common widescreen ratio in contemporary Hollywood films. The slight difference from 2.35:1 comes from adjustments in the SMPTE standard to account for the area between film frames.

1.85:1(US theatrical standard, also called "flat") is used for most non-scope theatrical releases in the United States. It sits between the 16:9 TV ratio and the wider 2.39:1 scope ratio, providing a modest widescreen look without extreme horizontal stretching.

Social Media Aspect Ratios

Each social media platform has preferred dimensions for images and video. Using the correct aspect ratio prevents cropping, black bars, and low-quality scaling. Below is a platform-by-platform breakdown.

  • YouTube— 16:9 (standard video), 9:16 (Shorts)
  • Instagram— 1:1 (1080×1080, square post), 4:5 (1080×1350, portrait post), 9:16 (1080×1920, Stories & Reels), 1.91:1 (1080×566, landscape post)
  • TikTok— 9:16 (1080×1920, full-screen vertical)
  • Facebook— 1.91:1 (link preview), 1:1 (feed image), 9:16 (Stories)
  • Twitter / X— 16:9 (post image), 3:1 (header banner at 1500×500)
  • LinkedIn— 1.91:1 (link preview), 1:1 (feed post)

Tip: When creating content for multiple platforms simultaneously, shoot in 9:16 vertical and crop to 1:1 or 4:5 for feed posts. This gives you the most flexibility from a single recording session.

How to Calculate Aspect Ratio

Aspect Ratio Formula

The aspect ratio is the proportional relationship between width and height. You can express it as a simple division or as a simplified integer ratio:

Decimal Ratio = width ÷ height

To get the simplified integer ratio (e.g., 16:9), divide both the width and height by their greatest common divisor (GCD):

Simplified Ratio = (width ÷ GCD) : (height ÷ GCD)

Step-by-Step Calculation Example

Given:A display with dimensions 2560×1440 pixels.

  1. Compute the decimal ratio: 2560 ÷ 1440 = 1.778
  2. Find the GCD of 2560 and 1440. The GCD is 320.
  3. Divide width by GCD: 2560 ÷ 320 = 8
  4. Divide height by GCD: 1440 ÷ 320 = 4.5
  5. Multiply both by 2 to get integers: 16 : 9

Result: 2560×1440 has a 16:9 aspect ratio, the same shape as 1920×1080 Full HD and 3840×2160 4K UHD.

Finding Aspect Ratio from Pixel Dimensions

Any resolution can be reduced to its aspect ratio by following these steps:

  1. Enter the width and height in pixels (e.g., 1920 and 1080).
  2. Calculate the GCD of the two numbers. For 1920 and 1080, the GCD is 120.
  3. Divide width by GCD: 1920 ÷ 120 = 16
  4. Divide height by GCD: 1080 ÷ 120 = 9
  5. The aspect ratio is 16:9.

This method works for any pair of dimensions. For example, 2560×1600 has a GCD of 160, giving 16:10 (or 8:5). A 4000×3000 photo has a GCD of 1000, giving 4:3.

Quick shortcut:Divide width by height on a calculator. If the result is approximately 1.78, the ratio is 16:9. If it's approximately 1.33, it's 4:3. If it's 1.5, it's 3:2. Memorizing these decimal values lets you identify common ratios at a glance.

How to Resize Images While Keeping Aspect Ratio

When you resize an image, video, or design element, you need to keep the original aspect ratio to prevent stretching or squashing. The formula is straightforward:

new_height = original_height × (new_width ÷ original_width)

Example:Resize a 1920×1080 image to 1280 pixels wide while preserving the 16:9 ratio:

  1. new_height = 1080 × (1280 ÷ 1920)
  2. new_height = 1080 × 0.6667
  3. new_height = 720

The resized image is 1280×720, which is still 16:9 (standard 720p HD).

Quality tips:

  • Always resize down from a larger original when possible. Upscaling introduces blur and artifacts.
  • Most image editors (Photoshop, GIMP, Figma) have a "lock aspect ratio" toggle — keep it enabled to avoid accidental distortion.
  • For web images, export at 2× the display size for sharp rendering on Retina and high-DPI screens.

Practical Applications

Understanding aspect ratios is essential across a wide range of creative and technical disciplines:

  • Video production and editing— Match your timeline settings to the delivery platform (16:9 for YouTube, 9:16 for TikTok).
  • Web design — Use the CSS aspect-ratio property to create responsive containers that maintain proportions at any viewport width.
  • Photography— Crop images to standard print ratios (3:2 for 4×6, 5:4 for 8×10) before sending to the printer.
  • Social media marketing— Prepare platform-specific assets in bulk (1:1 feed, 4:5 portrait, 9:16 stories) to maximize engagement.
  • Print and graphic design— Calculate scaled dimensions for posters, banners, and signage while keeping logos and photos proportionally correct.
  • Monitor and TV shopping— Compare screen shapes: a 34-inch ultrawide (21:9) and a 32-inch standard (16:9) have very different viewing experiences despite similar diagonal measurements.

For a deeper dive into aspect ratios across video, photo, and social media, read our Complete Guide to Aspect Ratios.