Input

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Enter dimensions or select a preset ratio.

1920 × 1080

Results

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Ratio, decimal value, CSS value, resize, and orientation.

Aspect ratio 16:9 1.777778:1
Resize result 1280 × 720 Same ratio
Closest common 16:9 Exact match
Orientation Landscape Width is greater than height
CSS aspect-ratio
aspect-ratio: 16 / 9;

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16:9
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Detected size 1920 × 1080 px

Aspect Ratio Calculator Instant Dimensions for Images, Videos & Social Media

Every designer, photographer, and content creator has been there: you Resize images and videos without stretching, cropping, or black bars. Enter width and height to find the aspect ratio, or choose a ratio and enter one dimension to calculate the other. The problem is almost always the same the aspect ratio was wrong before the work started.

This tool fixes that. Enter your dimensions and it gives you the correct ratio in under a second. Enter a target ratio and one dimension, and it calculates the missing number for you. No formulas, no guesswork, no rework.

Below you will find everything you need to know about aspect ratios what they mean, how they work, which one to use for each platform, and how to avoid the three display problems that ruin otherwise good content. You can generate stylish fonts with this stylish font generator.

What Is Aspect Ratio?

Aspect ratio is the proportional relationship between the width and height of any rectangular frame. It is written as two numbers separated by a colon for example, 16:9 or 4:3 where the first number always represents width and the second represents height.

The critical thing to understand: aspect ratio describes shape, not size.

A 160×90 thumbnail and a 3840×2160 cinema export are both 16:9. They look identical in shape. The only difference is sharpness. This is why the same ratio can apply to a phone screen, a cinema projector, or a social media post — the numbers just scale up or down while the proportions stay fixed.

Think of it like a recipe. A 16:9 ratio is the recipe for “widescreen.” Whether you bake a small version or a large version, the result has the same shape.

How does Aspect Ratio Calculator Works?

If you have an image with known pixel dimensions and want to find its ratio, the method involves three steps:

Step 1 — Find the Greatest Common Divisor (GCD) of the width and height. The GCD is the largest number that divides both values exactly.

Step 2 — Divide both the width and height by that GCD.

Step 3 — The result is your simplified aspect ratio.

Example 1: Width 1920 px, Height 1080 px. GCD of 1920 and 1080 = 120. 1920 ÷ 120 = 16 | 1080 ÷ 120 = 9 → Ratio: 16:9

Example 2: Width 1080 px, Height 1080 px. GCD = 1080. 1080 ÷ 1080 = 1 | 1080 ÷ 1080 = 1 → Ratio: 1:1

Example 3: Width 4000 px, Height 3000 px. GCD = 1000. 4000 ÷ 1000 = 4 | 3000 ÷ 1000 = 3 → Ratio: 4:3

The calculator above handles all of this automatically — just type in your dimensions.

Aspect Ratio vs. Resolution Two Different Things

These two terms are constantly confused. They describe completely different properties of an image:

Aspect ratio = shape Written with a colon (16:9). Tells you whether the frame is wide, tall, or square. Says nothing about pixel count or sharpness.

Resolution = size and quality Written with a multiplication sign (1920×1080). Tells you exactly how many pixels fill the frame. More pixels means sharper output.

Multiple resolutions can share the same aspect ratio. All four of these are 16:9:

Resolution

Label

Common Use

1280 × 720

HD / 720p

Minimum HD Fast Upload, Mobile

1920 × 1080

Full HD / 1080p

Standard for YouTube, streaming

2560 × 1440

QHD / 1440p

High-end monitors, gaming

3840 × 2160

4K / UHD

Professional video, future-proofing

7680 × 4320

8K

Broadcast archiving, high-end cinema

So when someone says “I need a 16:9 video,” you still need to decide the resolution separately. When someone says “1080p,” the aspect ratio (16:9) is already implied — both dimensions are specified, so the ratio is fixed.

Common Aspect Ratios and Where Each Is Used

Different industries have standardised on different shapes for different reasons. Here is a complete reference:

Ratio

Decimal

Name

Where You Will See It

16:9

1.78:1

Widescreen

YouTube, Netflix, TV, monitors, presentations

9:16

0.56:1

Vertical

TikTok, Instagram Reels, YouTube Shorts, Stories

4:3

1.33:1

Standard

iPads, older TVs, PowerPoint (legacy), CCTV

1:1

1.00:1

Square

Instagram feed posts, profile pictures, app icons

4:5

0.80:1

Portrait

Instagram feed portrait — maximum vertical space

3:2

1.50:1

DSLR Photo

35mm cameras, 4×6 photo prints, Surface laptops

5:4

1.25:1

Print

8×10 prints, medium format cameras

21:9

2.33:1

Ultrawide

Gaming monitors, cinematic video, panoramic shots

2:1

2.00:1

Univisium

Netflix originals, some smartphone screens

32:9

3.56:1

Super Ultrawide

Samsung Odyssey monitors, dual-screen replacement

2.39:1

2.39:1

Cinemascope

Theatrical films, anamorphic lens shooting

1.85:1

1.85:1

Theatrical Flat

Standard cinema projection, IMAX digital

Use the dedicated pages for detailed guidance on each: → 16:9 Aspect Ratio Calculator → 4:3 Aspect Ratio Calculator → Image Aspect Ratio Guide → Video Aspect Ratio Guide

Social Media Aspect Ratios — 2026 Reference

Every platform compresses and displays images differently. Uploading at the wrong dimensions causes automatic cropping that can remove faces, text, or branded elements you specifically placed at the edges. Here are the current recommended dimensions for each major platform:

Instagram

Format

Dimensions

Ratio

Notes

Feed post (square)

1080 × 1080

1:1

Classic format, safe for all feeds

Feed post (portrait)

1080 × 1350

4:5

Recommended — takes up more vertical scroll space

Feed post (landscape)

1080 × 566

1.91:1

Less common, gets compressed in feed

Story / Reel

1080 × 1920

9:16

Keep key content away from top and bottom 15% (UI elements)

Profile picture

320 × 320

1:1

Displays as a circle, keep subject centred

YouTube

Format

Dimensions

Ratio

Notes

Standard video

1920 × 1080

16:9

Required minimum for full HD

4K video

3840 × 2160

16:9

Upload at 4K even from 1080p sources for better compression

Shorts

1080 × 1920

9:16

Must be under 60 seconds to appear in Shorts shelf

Thumbnail

1280 × 720

16:9

Max 2MB, use bold text readable at 150px wide

Channel banner

2560 × 1440

16:9

Safe area for all devices: centre 1546 × 423 px

TikTok

Format

Dimensions

Ratio

Notes

Video

1080 × 1920

9:16

Only format that fills the screen without bars

Profile picture

200 × 200

1:1

Keep subject well centred

Important for TikTok: Keep all text, face, and key visuals between 15% from the top and 20% from the bottom. The platform’s caption and reaction UI covers these zones on many devices.

X (Twitter)

Format

Dimensions

Ratio

Notes

Post image

1600 × 900

16:9

Displays inline; crops to roughly 16:9 in feed

Header

1500 × 500

3:1

Safe area is centre portion

LinkedIn

Format

Dimensions

Ratio

Notes

Post image

1200 × 628

1.91:1

Standard for link previews and image posts

Company banner

1584 × 396

4:1

Crops differently on mobile

Profile banner

1584 × 396

4:1

—

Facebook

Format

Dimensions

Ratio

Notes

Post image

1200 × 630

1.91:1

Standard link preview size

Cover photo

820 × 312

2.63:1

Displays at 820 × 312 on desktop, 640 × 360 on mobile

Profile picture

180 × 180

1:1

Displays as 170 × 170

Pinterest

Format

Dimensions

Ratio

Notes

Standard Pin

1000 × 1500

2:3

Optimal ratio for feed visibility

Square Pin

1000 × 1000

1:1

Works but occupies less feed space

Why Does Aspect Ratio Matter? The Three Problems It Causes

Getting the ratio wrong before you create or upload always produces one of three outcomes — and none of them are good:

1. Stretching The platform forces your image into a differently shaped frame by distorting the pixels. Circles become ovals. Faces look wider or taller than real life. Text looks wrong. This usually happens when a video editor scales footage to fill a frame instead of cropping it, or when a social media manager uploads an image without checking its dimensions first.

2. Letterboxing and Pillarboxing Black (or blurred) bars fill the empty space between your content and the frame. Letterbox bars appear on the top and bottom when your content is narrower than the screen — this is what you see watching an old widescreen film on a 4:3 TV. Pillarbox bars appear on the sides when your content is taller — this is what you see watching a TikTok video on a laptop in full screen. The content is undistorted, but the bars look unprofessional for branded or commercial content.

3. Cropping The platform trims the edges automatically to force a fit. Instagram, TikTok, and YouTube all do this when you upload at the wrong ratio. The problem is that the cropping algorithm does not know what is important in your frame — it simply removes pixels from the edges. Faces, logos, subtitles, and call-to-action text placed near the edges regularly disappear. The fix is always the same: set the correct ratio before you start creating, not after.

Aspect Ratio by Field

Photography

Most DSLR and mirrorless cameras capture in 3:2, a ratio inherited directly from 35mm film. Micro Four Thirds systems use 4:3. Phone cameras shoot in 4:3 by default but can switch to 16:9 by cropping the sensor.

The catch: standard print sizes do not match camera sensor ratios. A 4×6 print is 3:2, which matches a DSLR. But a common 8×10 print is 5:4 — if you send a 3:2 DSLR photo to be printed at 8×10 without cropping first, the lab will crop it for you, and the result may not be what you intended. Check the image aspect ratio guide for a full table of print size ratios.

Video

16:9 is the default for virtually every digital video format — YouTube, Netflix, broadcast TV, web video. The exceptions are cinema (which uses 1.85:1 for flat theatrical or 2.39:1 for anamorphic widescreen) and vertical social video (which uses 9:16). The black bars you see when watching a film on your TV usually mean the movie was shot wider than 16:9 and your TV is displaying the full frame with letterbox bars rather than cropping it to fill the screen. See the video aspect ratio guide for platform-specific export settings.

Web Design

Hero images typically use 16:9 or 2:1 for a widescreen banner feel. Product images are usually 1:1 for consistent grid layouts. Open Graph images — the preview image that appears when someone shares a link on social media — need to be 1.91:1 (1200 × 630 pixels) to display correctly on all platforms. CSS now has a native aspect-ratio property that locks an element’s shape regardless of its content size, which makes it straightforward to enforce consistent ratios across responsive layouts without JavaScript.

Portrait vs. Landscape

These terms describe orientation, not a specific ratio:

Landscape means wider than tall. Traditional screens TVs, monitors, cinema — are landscape. Ratios like 16:9 and 4:3 are landscape formats.

Portrait means taller than wide. Smartphones held vertically are portrait. The 9:16 ratio is the portrait equivalent of 16:9 — it uses exactly the same numbers, just swapped.

The shift toward vertical content is driven by phone usage. People hold their phones upright more than 90% of the time when consuming content. TikTok, Instagram Reels, and YouTube Shorts were all built specifically for this behaviour, which is why 9:16 has become just as important as 16:9 for creators today.

One practical note: if you are shooting content intended for both horizontal platforms (YouTube main feed) and vertical platforms (Shorts, Reels), plan your shots with the centre of the frame as the primary subject area. That way the same footage can be cropped to both 16:9 and 9:16 without losing the main content.

FAQs

Standard YouTube videos should be 16:9 at 1920×1080 pixels (1080p) as a minimum. If you have 4K footage, export at 3840×2160. YouTube Shorts use 9:16 at 1080×1920. Thumbnails are 16:9 at 1280×720 with a maximum file size of 2MB.

Instagram supports multiple ratios depending on the format. Feed posts can be 1:1 (square), 4:5 (portrait — recommended for maximum screen coverage), or 1.91:1 (landscape). Stories and Reels use 9:16. Using 4:5 for feed posts gives your image more vertical space in the scroll, which typically improves visibility.

16:9 is roughly 33% wider than 4:3 at the same height. 16:9 is the modern widescreen standard used by nearly all TVs, monitors, and video platforms. 4:3 is the older “fullscreen” format used by early television and still current for iPad displays and some presentation projectors. On a 16:9 screen, a 4:3 video gets pillarbox bars on both sides. On a 4:3 screen, a 16:9 video gets letterbox bars top and bottom.

GCD stands for Greatest Common Divisor the largest number that divides both the width and height exactly. Dividing both dimensions by their GCD gives you the simplest whole-number ratio. For 1920×1080, the GCD is 120, so dividing both by 120 gives 16:9. The tool on this page does this automatically.

Yes. The same ratio rules apply to both. Whether you are working with a still image in Photoshop, a video sequence in Premiere, or a design canvas in Figma, the calculator works the same way — enter width and height, get the ratio, or enter a ratio and one dimension to find the other.

Black bars appear when the aspect ratio of the video does not match the aspect ratio of your screen. Top and bottom bars (letterboxing) mean the video is wider than your screen. Side bars (pillarboxing) mean the video is taller (or more square) than your screen. The video itself is not distorted the bars preserve the original ratio. To remove them, you would need to crop the video to match your screen, which would cut off some of the frame.

Most smartphones default to 4:3 for photos and 16:9 for video. Some phones offer a 1:1 option. Modern flagship phones (iPhone 14+, Samsung S24+) have sensors closer to 4:3, and the 16:9 video mode works by cropping the top and bottom of the sensor area. For TikTok and Reels content, switch your phone camera to 9:16 video mode (usually labelled as the default video recording orientation) rather than cropping a 16:9 video later.

It depends on the print size. A 4×6 print is 3:2, matching most DSLR cameras. A 5×7 print is roughly 7:5. An 8×10 print is 5:4. An 8×12 print is back to 3:2. Always check the ratio of your intended print size against your source image before ordering if they don’t match, crop to the correct ratio in your editing software first rather than letting the print lab crop it automatically.

Conculsion

We have come to an end for the aspect ratio calculator which is a perfect tool for keeping the check and balance of your images and videos to look professional. It is a tool that simplifies the process of measuring images as it provides accurate dimensions quickly and easily. 

Once you master it, all the content you create will have intended proportions and impact. So, grab the chance, and become a pro by keeping your content correctly formatted by using our very own ratio calculator.